averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity
Files
623aba17860ed847ea3bb00729c3a3d758cf9f9d
swift-mirror/lib/Sema/CSApply.cpp
Joe Groff 623aba1786 Encapsulate Substitution's state. 
Expose Substitution's archetype, replacement, and conformances only through getters so we can actually assert invariants about them. To start, require  replacement types to be materializable in order to catch cases where the type-checker tries to bind type variables to lvalue or inout types, and require the conformance array to match the number of protocol conformances required by the archetype. This exposes some latent bugs in the test suite I've marked as failures for now:

- test/Constraints/overload.swift was quietly suffering from <rdar://problem/17507421>, but we didn't notice because we never tried to codegen it.
- test/SIL/Parser/array_roundtrip.swift doesn't correctly roundtrip substitutions, which I filed as <rdar://problem/17781140>.

Swift SVN r20418
2014-07-23 18:00:38 +00:00

5245 lines
203 KiB
C++
Raw Blame History

//===--- CSApply.cpp - Constraint Application -----------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements application of a solution to a constraint
// system to a particular expression, resulting in a
// fully-type-checked expression.
//
//===----------------------------------------------------------------------===//
#include "ConstraintSystem.h"
#include "swift/AST/ArchetypeBuilder.h"
#include "swift/AST/ASTVisitor.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/Attr.h"
#include "swift/Parse/Lexer.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/SaveAndRestore.h"
using namespace swift;
using namespace constraints;
/// \brief Retrieve the fixed type for the given type variable.
Type Solution::getFixedType(TypeVariableType *typeVar) const {
auto knownBinding = typeBindings.find(typeVar);
assert(knownBinding != typeBindings.end());
return knownBinding->second;
}
Type Solution::computeSubstitutions(Type origType, DeclContext *dc,
Type openedType,
SmallVectorImpl<Substitution> &substitutions) const {
auto &tc = getConstraintSystem().getTypeChecker();
auto &ctx = tc.Context;
// Gather the substitutions from archetypes to concrete types, found
// by identifying all of the type variables in the original type
// FIXME: It's unfortunate that we're using archetypes here, but we don't
// have another way to map from type variables back to dependent types (yet);
TypeSubstitutionMap typeSubstitutions;
auto type = openedType.transform([&](Type type) -> Type {
if (auto tv = dyn_cast<TypeVariableType>(type.getPointer())) {
auto archetype = tv->getImpl().getArchetype();
auto simplified = getFixedType(tv);
typeSubstitutions[archetype] = simplified;
return SubstitutedType::get(archetype, simplified,
tc.Context);
}
return type;
});
auto currentModule = getConstraintSystem().DC->getParentModule();
ArchetypeType *currentArchetype = nullptr;
Type currentReplacement;
SmallVector<ProtocolConformance *, 4> currentConformances;
ArrayRef<Requirement> requirements;
if (auto genericFn = origType->getAs<GenericFunctionType>()) {
requirements = genericFn->getRequirements();
} else {
requirements = dc->getDeclaredTypeOfContext()->getAnyNominal()
->getGenericRequirements();
}
for (const auto &req : requirements) {
// Drop requirements for parameters that have been constrained away to
// concrete types.
auto firstArchetype
= ArchetypeBuilder::mapTypeIntoContext(dc, req.getFirstType())
->getAs<ArchetypeType>();
if (!firstArchetype)
continue;
switch (req.getKind()) {
case RequirementKind::Conformance:
// If this is a protocol conformance requirement, get the conformance
// and record it.
if (auto protoType = req.getSecondType()->getAs<ProtocolType>()) {
assert(firstArchetype == currentArchetype
&& "Archetype out-of-sync");
ProtocolConformance *conformance = nullptr;
Type replacement = currentReplacement;
bool conforms = tc.conformsToProtocol(replacement,
protoType->getDecl(),
getConstraintSystem().DC,
&conformance);
assert((conforms ||
replacement->isExistentialType() ||
firstArchetype->getIsRecursive() ||
replacement->is<GenericTypeParamType>()) &&
"Constraint system missed a conformance?");
(void)conforms;
assert(conformance ||
replacement->isExistentialType() ||
replacement->is<ArchetypeType>() ||
replacement->is<GenericTypeParamType>());
currentConformances.push_back(conformance);
break;
}
break;
case RequirementKind::SameType:
// Same-type requirements aren't recorded in substitutions.
break;
case RequirementKind::WitnessMarker:
// Flush the current conformances.
if (currentArchetype) {
substitutions.push_back({
currentArchetype,
currentReplacement,
ctx.AllocateCopy(currentConformances)
});
currentConformances.clear();
}
// Each witness marker starts a new substitution.
currentArchetype = firstArchetype;
currentReplacement = tc.substType(currentModule, currentArchetype,
typeSubstitutions);
break;
}
}
// Flush the final conformances.
if (currentArchetype) {
substitutions.push_back({
currentArchetype,
currentReplacement,
ctx.AllocateCopy(currentConformances),
});
currentConformances.clear();
}
return type;
}
/// \brief Find a particular named function witness for a type that conforms to
/// the given protocol.
///
/// \param tc The type check we're using.
///
/// \param dc The context in which we need a witness.
///
/// \param type The type whose witness to find.
///
/// \param proto The protocol to which the type conforms.
///
/// \param name The name of the requirement.
///
/// \param diag The diagnostic to emit if the protocol definition doesn't
/// have a requirement with the given name.
///
/// \returns The named witness.
template <typename DeclTy>
static DeclTy *findNamedWitnessImpl(TypeChecker &tc, DeclContext *dc, Type type,
ProtocolDecl *proto, Identifier name,
Diag<> diag) {
// Find the named requirement.
DeclTy *requirement = nullptr;
for (auto member : proto->getMembers()) {
auto d = dyn_cast<DeclTy>(member);
if (!d || !d->hasName())
continue;
if (d->getName() == name) {
requirement = d;
break;
}
}
if (!requirement || requirement->isInvalid()) {
tc.diagnose(proto->getLoc(), diag);
return nullptr;
}
// Find the member used to satisfy the named requirement.
ProtocolConformance *conformance = 0;
bool conforms = tc.conformsToProtocol(type, proto, dc, &conformance);
if (!conforms)
return nullptr;
// For an archetype, just return the requirement from the protocol. There
// are no protocol conformance tables.
if (type->is<ArchetypeType>()) {
return requirement;
}
assert(conformance && "Missing conformance information");
// FIXME: Dropping substitutions here.
return cast<DeclTy>(conformance->getWitness(requirement, &tc).getDecl());
}
static FuncDecl *findNamedWitness(TypeChecker &tc, DeclContext *dc, Type type,
ProtocolDecl *proto, Identifier name,
Diag<> diag) {
return findNamedWitnessImpl<FuncDecl>(tc, dc, type, proto, name, diag);
}
static VarDecl *findNamedPropertyWitness(TypeChecker &tc, DeclContext *dc,
Type type, ProtocolDecl *proto,
Identifier name, Diag<> diag) {
return findNamedWitnessImpl<VarDecl>(tc, dc, type, proto, name, diag);
}
/// Adjust the given type to become the self type when referring to
/// the given member.
static Type adjustSelfTypeForMember(Type baseTy, ValueDecl *member,
bool IsDirectPropertyAccess,
DeclContext *UseDC) {
auto baseObjectTy = baseTy->getLValueOrInOutObjectType();
if (auto func = dyn_cast<AbstractFunctionDecl>(member)) {
// If 'self' is an inout type, turn the base type into an lvalue
// type with the same qualifiers.
auto selfTy = func->getType()->getAs<AnyFunctionType>()->getInput();
if (selfTy->is<InOutType>()) {
// Unless we're looking at a nonmutating existential member. In which
// case, the member will be modeled as an inout but ExistentialMemberRef
// and ArchetypeMemberRef want to take the base as an rvalue.
if (auto *fd = dyn_cast<FuncDecl>(func))
if (!fd->isMutating() &&
(baseObjectTy->isExistentialType() ||
baseObjectTy->is<ArchetypeType>()))
return baseObjectTy;
return InOutType::get(baseObjectTy);
}
// Otherwise, return the rvalue type.
return baseObjectTy;
}
// If the base of the access is mutable, then we may be invoking a getter or
// setter and the base needs to be mutable.
if (auto *VD = dyn_cast<VarDecl>(member)) {
if (VD->hasAccessorFunctions() && baseTy->is<InOutType>() &&
!IsDirectPropertyAccess)
return InOutType::get(baseObjectTy);
// If the member is immutable in this context, the base is always an
// unqualified baseObjectTy.
if (!VD->isSettable(UseDC))
return baseObjectTy;
}
// If the base of the subscript is mutable, then we may be invoking a mutable
// getter or setter.
if (isa<SubscriptDecl>(member) && !baseTy->hasReferenceSemantics() &&
baseTy->is<InOutType>())
return InOutType::get(baseObjectTy);
// Accesses to non-function members in value types are done through an @lvalue
// type.
if (baseTy->is<InOutType>())
return LValueType::get(baseObjectTy);
// Accesses to members in values of reference type (classes, metatypes) are
// always done through a the reference to self. Accesses to value types with
// a non-mutable self are also done through the base type.
return baseTy;
}
/// Return true if a MemberReferenceExpr with the specified base and member in
/// the specified DeclContext should be implicitly marked as
/// "isDirectPropertyAccess".
static bool isImplicitDirectMemberReference(Expr *base, VarDecl *member,
DeclContext *DC) {
// Properties that have storage and accessors are frequently accessed through
// accessors. However, in the init and destructor methods for the type
// immediately containing the property, accesses are done direct.
if (auto *AFD_DC = dyn_cast<AbstractFunctionDecl>(DC))
if (member->hasStorage() &&
// In a ctor or dtor.
(isa<ConstructorDecl>(AFD_DC) || isa<DestructorDecl>(AFD_DC)) &&
// Ctor or dtor are for immediate class, not a derived class.
AFD_DC->getParent()->getDeclaredTypeOfContext()->getCanonicalType() ==
member->getDeclContext()->getDeclaredTypeOfContext()->getCanonicalType() &&
// Is a "self.property" reference.
isa<DeclRefExpr>(base) &&
AFD_DC->getImplicitSelfDecl() == cast<DeclRefExpr>(base)->getDecl()) {
// Access this directly instead of going through (e.g.) observing or
// trivial accessors.
return true;
}
// If the value is always directly accessed from this context, do it.
return member->isUseFromContextDirect(DC);
}
namespace {
/// \brief Rewrites an expression by applying the solution of a constraint
/// system to that expression.
class ExprRewriter : public ExprVisitor<ExprRewriter, Expr *> {
public:
ConstraintSystem &cs;
DeclContext *dc;
const Solution &solution;
private:
/// \brief Coerce the given tuple to another tuple type.
///
/// \param expr The expression we're converting.
///
/// \param fromTuple The tuple type we're converting from, which is the same
/// as \c expr->getType().
///
/// \param toTuple The tuple type we're converting to.
///
/// \param locator Locator describing where this tuple conversion occurs.
///
/// \param sources The sources of each of the elements to be used in the
/// resulting tuple, as provided by \c computeTupleShuffle.
///
/// \param variadicArgs The source indices that are mapped to the variadic
/// parameter of the resulting tuple, as provided by \c computeTupleShuffle.
Expr *coerceTupleToTuple(Expr *expr, TupleType *fromTuple,
TupleType *toTuple,
ConstraintLocatorBuilder locator,
SmallVectorImpl<int> &sources,
SmallVectorImpl<unsigned> &variadicArgs);
/// \brief Coerce the given scalar value to the given tuple type.
///
/// \param expr The expression to be coerced.
/// \param toTuple The tuple type to which the expression will be coerced.
/// \param toScalarIdx The index of the scalar field within the tuple type
/// \c toType.
/// \param locator Locator describing where this conversion occurs.
///
/// \returns The coerced expression, whose type will be equivalent to
/// \c toTuple.
Expr *coerceScalarToTuple(Expr *expr, TupleType *toTuple,
int toScalarIdx,
ConstraintLocatorBuilder locator);
/// \brief Coerce the given value to existential type.
///
/// \param expr The expression to be coerced.
/// \param toType The tupe to which the expression will be coerced.
/// \param locator Locator describing where this conversion occurs.
///
/// \return The coerced expression, whose type will be equivalent to
/// \c toType.
Expr *coerceExistential(Expr *expr, Type toType,
ConstraintLocatorBuilder locator);
/// \brief Coerce the given value to an existential metatype type.
///
/// \param expr The expression to be coerced.
/// \param toType The tupe to which the expression will be coerced.
/// \param locator Locator describing where this conversion occurs.
///
/// \return The coerced expression, whose type will be equivalent to
/// \c toType.
Expr *coerceExistentialMetatype(Expr *expr, Type toType,
ConstraintLocatorBuilder locator);
/// \brief Coerce the expression to another type via a user-defined
/// conversion.
///
/// \param expr The expression to be coerced.
/// \param toType The tupe to which the expression will be coerced.
/// \param locator Locator describing where this conversion occurs.
///
/// \return The coerced expression, whose type will be equivalent to
/// \c toType.
Expr *coerceViaUserConversion(Expr *expr, Type toType,
ConstraintLocatorBuilder locator);
/// \brief Coerce an expression of (possibly unchecked) optional
/// type to have a different (possibly unchecked) optional type.
Expr *coerceOptionalToOptional(Expr *expr, Type toType,
ConstraintLocatorBuilder locator);
/// \brief Coerce an expression of implicitly unwrapped optional type to its
/// underlying value type, in the correct way for an implicit
/// look-through.
Expr *coerceImplicitlyUnwrappedOptionalToValue(Expr *expr, Type objTy,
ConstraintLocatorBuilder locator);
public:
/// \brief Build a reference to the given declaration.
Expr *buildDeclRef(ValueDecl *decl, SourceLoc loc, Type openedType,
ConstraintLocatorBuilder locator,
bool specialized, bool implicit,
bool isDirectPropertyAccess) {
// Determine the declaration selected for this overloaded reference.
auto &ctx = cs.getASTContext();
// If this is a member of a nominal type, build a reference to the
// member with an implied base type.
if (decl->getDeclContext()->isTypeContext() && isa<FuncDecl>(decl)) {
assert(isa<FuncDecl>(decl) && "Can only refer to functions here");
assert(cast<FuncDecl>(decl)->isOperator() && "Must be an operator");
auto openedFnType = openedType->castTo<FunctionType>();
auto baseTy = simplifyType(openedFnType->getInput())
->getRValueInstanceType();
Expr *base = TypeExpr::createImplicitHack(loc, baseTy, ctx);
return buildMemberRef(base, openedType, SourceLoc(), decl,
loc, openedFnType->getResult(),
locator, implicit, isDirectPropertyAccess);
}
// If this is a declaration with generic function type, build a
// specialized reference to it.
if (auto genericFn
= decl->getInterfaceType()->getAs<GenericFunctionType>()) {
auto dc = decl->getPotentialGenericDeclContext();
SmallVector<Substitution, 4> substitutions;
auto type = solution.computeSubstitutions(genericFn, dc, openedType,
substitutions);
return new (ctx) DeclRefExpr(ConcreteDeclRef(ctx, decl, substitutions),
loc, implicit, isDirectPropertyAccess,
type);
}
auto type = simplifyType(openedType);
return new (ctx) DeclRefExpr(decl, loc, implicit, isDirectPropertyAccess,
type);
}
/// Describes an opened existential that has not yet been closed.
struct OpenedExistential {
/// The existential value being opened.
Expr *ExistentialValue;
/// The opaque value (of archetype type) stored within the
/// existential.
OpaqueValueExpr *OpaqueValue;
};
/// A mapping from archetype types that resulted from opening an
/// existential to the opened existential. This mapping captures
/// only those existentials that have been opened, but for which
/// we have not yet created an \c OpenExistentialExpr.
llvm::SmallDenseMap<ArchetypeType *, OpenedExistential> OpenedExistentials;
/// Open an existential value into a new, opaque value of
/// archetype type.
///
/// \param base An expression of existential type whose value will
/// be opened.
///
/// \returns A pair (expr, type) that provides a reference to the value
/// stored within the expression or its metatype (if the base was a
/// metatype) and the new archetype that describes the dynamic type stored
/// within the existential.
std::tuple<Expr *, ArchetypeType *>
openExistentialReference(Expr *base) {
auto &tc = cs.getTypeChecker();
base = tc.coerceToRValue(base);
auto baseTy = base->getType()->getRValueType();
bool isMetatype = false;
if (auto metaTy = baseTy->getAs<AnyMetatypeType>()) {
isMetatype = true;
baseTy = metaTy->getInstanceType();
}
assert(baseTy->isAnyExistentialType() && "Type must be existential");
// Create the archetype.
SmallVector<ProtocolDecl *, 4> protocols;
auto &ctx = tc.Context;
baseTy->getAnyExistentialTypeProtocols(protocols);
auto archetype = ArchetypeType::getOpened(baseTy);
// Create the opaque opened value. If we started with a
// metatype, it's a metatype.
Type opaqueType = archetype;
if (isMetatype)
opaqueType = MetatypeType::get(archetype);
auto archetypeVal = new (ctx) OpaqueValueExpr(base->getLoc(), opaqueType);
archetypeVal->setUniquelyReferenced(true);
// Record this opened existential.
OpenedExistentials[archetype] = { base, archetypeVal };
return std::make_tuple(archetypeVal, archetype);
}
/// Is the given function a constructor of a class or protocol?
/// Such functions are subject to DynamicSelf manipulations.
///
/// We want to avoid taking the DynamicSelf paths for other
/// constructors for two reasons:
/// - it's an unnecessary cost
/// - optionality preservation has a problem with constructors on
/// optional types
static bool isPolymorphicConstructor(AbstractFunctionDecl *fn) {
if (!isa<ConstructorDecl>(fn))
return false;
DeclContext *parent = fn->getParent();
if (auto extension = dyn_cast<ExtensionDecl>(parent))
parent = extension->getExtendedType()->getAnyNominal();
return (isa<ClassDecl>(parent) || isa<ProtocolDecl>(parent));
}
/// \brief Build a new member reference with the given base and member.
Expr *buildMemberRef(Expr *base, Type openedFullType, SourceLoc dotLoc,
ValueDecl *member, SourceLoc memberLoc,
Type openedType, ConstraintLocatorBuilder locator,
bool Implicit, bool IsDirectPropertyAccess) {
auto &tc = cs.getTypeChecker();
auto &context = tc.Context;
bool isSuper = base->isSuperExpr();
Type baseTy = base->getType()->getRValueType();
// Explicit member accesses are permitted to implicitly look
// through ImplicitlyUnwrappedOptional<T>.
if (!Implicit) {
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(baseTy)) {
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy, locator);
if (!base) return nullptr;
baseTy = objTy;
}
}
// Figure out the actual base type, and whether we have an instance of
// that type or its metatype.
bool baseIsInstance = true;
if (auto baseMeta = baseTy->getAs<AnyMetatypeType>()) {
baseIsInstance = false;
baseTy = baseMeta->getInstanceType();
}
// Produce a reference to the member, the type of the container it
// resides in, and the type produced by the reference itself.
Type containerTy;
ConcreteDeclRef memberRef;
Type refTy;
Type dynamicSelfFnType;
if (openedFullType->hasTypeVariable()) {
// We require substitutions. Figure out what they are.
// Figure out the declaration context where we'll get the generic
// parameters.
auto dc = member->getPotentialGenericDeclContext();
// Build a reference to the generic member.
SmallVector<Substitution, 4> substitutions;
refTy = solution.computeSubstitutions(member->getInterfaceType(),
dc,
openedFullType,
substitutions);
memberRef = ConcreteDeclRef(context, member, substitutions);
if (auto openedFullFnType = openedFullType->getAs<FunctionType>()) {
auto openedBaseType = openedFullFnType->getInput()
->getRValueInstanceType();
containerTy = solution.simplifyType(tc, openedBaseType);
}
} else {
// No substitutions required; the declaration reference is simple.
containerTy = member->getDeclContext()->getDeclaredTypeOfContext();
memberRef = member;
refTy = tc.getUnopenedTypeOfReference(member, Type(), dc,
/*wantInterfaceType=*/true);
}
// If this is a method whose result type is dynamic Self, or a
// construction, replace the result type with the actual object type.
if (auto func = dyn_cast<AbstractFunctionDecl>(member)) {
if ((isa<FuncDecl>(func) && cast<FuncDecl>(func)->hasDynamicSelf()) ||
isPolymorphicConstructor(func)) {
// For a DynamicSelf method on an existential, open up the
// existential.
if (func->getExtensionType()->is<ProtocolType>() &&
baseTy->isAnyExistentialType()) {
std::tie(base, baseTy) = openExistentialReference(base);
containerTy = baseTy;
openedType = openedType->replaceCovariantResultType(
baseTy,
func->getNumParamPatterns()-1);
// The member reference is a specialized declaration
// reference that replaces the Self of the protocol with
// the existential type; change it to refer to the opened
// archetype type.
// FIXME: We should do this before we create the
// specialized declaration reference, but that requires
// redundant hasDynamicSelf checking.
auto oldSubstitutions = memberRef.getSubstitutions();
SmallVector<Substitution, 4> newSubstitutions(
oldSubstitutions.begin(),
oldSubstitutions.end());
auto &selfSubst = newSubstitutions.front();
assert(selfSubst.getArchetype()->getSelfProtocol() &&
"Not the Self archetype for a protocol?");
unsigned numConformances = selfSubst.getConformances().size();
auto newConformances
= context.Allocate<ProtocolConformance *>(numConformances);
std::fill(newConformances.begin(), newConformances.end(), nullptr);
selfSubst = {
selfSubst.getArchetype(),
baseTy,
newConformances,
};
memberRef = ConcreteDeclRef(context, memberRef.getDecl(),
newSubstitutions);
}
refTy = refTy->replaceCovariantResultType(containerTy,
func->getNumParamPatterns());
dynamicSelfFnType = refTy->replaceCovariantResultType(
baseTy,
func->getNumParamPatterns());
// If the type after replacing DynamicSelf with the provided base
// type is no different, we don't need to perform a conversion here.
if (refTy->isEqual(dynamicSelfFnType))
dynamicSelfFnType = nullptr;
}
}
// If we're referring to the member of a module, it's just a simple
// reference.
if (baseTy->is<ModuleType>()) {
assert(!IsDirectPropertyAccess &&
"Direct property access doesn't make sense for this");
assert(!dynamicSelfFnType && "No reference type to convert to");
Expr *ref = new (context) DeclRefExpr(memberRef, memberLoc, Implicit);
ref->setType(refTy);
return new (context) DotSyntaxBaseIgnoredExpr(base, dotLoc, ref);
}
// Otherwise, we're referring to a member of a type.
// Is it an archetype or existential member?
bool isArchetypeOrExistentialRef
= isa<ProtocolDecl>(member->getDeclContext()) &&
(baseTy->is<ArchetypeType>() || baseTy->isAnyExistentialType());
// If we are referring to an optional member of a protocol.
if (isArchetypeOrExistentialRef &&
member->getAttrs().hasAttribute<OptionalAttr>()) {
auto proto =tc.getProtocol(memberLoc, KnownProtocolKind::AnyObject);
if (!proto)
return nullptr;
baseTy = proto->getDeclaredType();
}
// References to properties with accessors and storage usually go
// through the accessors, but sometimes are direct.
if (auto *VD = dyn_cast<VarDecl>(member))
IsDirectPropertyAccess |= isImplicitDirectMemberReference(base, VD, dc);
if (baseIsInstance) {
// Convert the base to the appropriate container type, turning it
// into an lvalue if required.
Type selfTy;
if (isArchetypeOrExistentialRef)
selfTy = baseTy;
else
selfTy = containerTy;
// If the base is already an lvalue with the right base type, we can
// pass it as an inout qualified type.
if (selfTy->isEqual(baseTy) && !selfTy->hasReferenceSemantics())
if (base->getType()->is<LValueType>())
selfTy = InOutType::get(selfTy);
base = coerceObjectArgumentToType(
base, selfTy, member, IsDirectPropertyAccess,
locator.withPathElement(ConstraintLocator::MemberRefBase));
} else {
// Convert the base to an rvalue of the appropriate metatype.
base = coerceToType(base,
MetatypeType::get(isArchetypeOrExistentialRef
? baseTy
: containerTy),
locator.withPathElement(
ConstraintLocator::MemberRefBase));
if (!base)
return nullptr;
base = tc.coerceToRValue(base);
}
assert(base && "Unable to convert base?");
// Handle archetype and existential references.
if (isArchetypeOrExistentialRef) {
assert(!IsDirectPropertyAccess &&
"Direct property access doesn't make sense for this");
assert(!dynamicSelfFnType &&
"Archetype/existential DynamicSelf with extra conversion");
Expr *ref;
if (member->getAttrs().hasAttribute<OptionalAttr>()) {
base = tc.coerceToRValue(base);
if (!base) return nullptr;
ref = new (context) DynamicMemberRefExpr(base, dotLoc, memberRef,
memberLoc);
} else {
assert(!dynamicSelfFnType && "Converted type doesn't make sense here");
ref = new (context) MemberRefExpr(base, dotLoc, memberRef,
memberLoc, Implicit,
IsDirectPropertyAccess);
cast<MemberRefExpr>(ref)->setIsSuper(isSuper);
}
ref->setImplicit(Implicit);
ref->setType(simplifyType(openedType));
return ref;
}
// For types and properties, build member references.
if (isa<TypeDecl>(member) || isa<VarDecl>(member)) {
assert(!dynamicSelfFnType && "Converted type doesn't make sense here");
auto result
= new (context) MemberRefExpr(base, dotLoc, memberRef,
memberLoc, Implicit,
IsDirectPropertyAccess);
result->setIsSuper(isSuper);
// Skip the synthesized 'self' input type of the opened type.
result->setType(simplifyType(openedType));
return result;
}
assert(!IsDirectPropertyAccess &&
"Direct property access doesn't make sense for this");
// Handle all other references.
Expr *ref = new (context) DeclRefExpr(memberRef, memberLoc, Implicit);
ref->setType(refTy);
// If the reference needs to be converted, do so now.
if (dynamicSelfFnType) {
ref = new (context) CovariantFunctionConversionExpr(ref,
dynamicSelfFnType);
}
ApplyExpr *apply;
if (isa<ConstructorDecl>(member)) {
// FIXME: Provide type annotation.
apply = new (context) ConstructorRefCallExpr(ref, base);
} else if (!baseIsInstance && member->isInstanceMember()) {
// Reference to an unbound instance method.
return new (context) DotSyntaxBaseIgnoredExpr(base, dotLoc, ref);
} else {
assert((!baseIsInstance || member->isInstanceMember()) &&
"can't call a static method on an instance");
apply = new (context) DotSyntaxCallExpr(ref, dotLoc, base);
}
return finishApply(apply, openedType, nullptr);
}
/// \brief Build a new dynamic member reference with the given base and
/// member.
Expr *buildDynamicMemberRef(Expr *base, SourceLoc dotLoc, ValueDecl *member,
SourceLoc memberLoc, Type openedType,
ConstraintLocatorBuilder locator) {
auto &context = cs.getASTContext();
// If we're specializing a polymorphic function, compute the set of
// substitutions and form the member reference.
Optional<ConcreteDeclRef> memberRef(member);
if (auto func = dyn_cast<FuncDecl>(member)) {
auto resultTy = func->getType()->castTo<AnyFunctionType>()->getResult();
(void)resultTy;
assert(!resultTy->is<PolymorphicFunctionType>() &&
"Polymorphic function type slipped through");
}
// The base must always be an rvalue.
base = cs.getTypeChecker().coerceToRValue(base);
if (!base) return nullptr;
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(base->getType())) {
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy, locator);
if (!base) return nullptr;
}
auto result = new (context) DynamicMemberRefExpr(base, dotLoc, *memberRef,
memberLoc);
result->setType(simplifyType(openedType));
return result;
}
/// \brief Describes either a type or the name of a type to be resolved.
typedef llvm::PointerUnion<Identifier, Type> TypeOrName;
/// \brief Convert the given literal expression via a protocol pair.
///
/// This routine handles the two-step literal conversion process used
/// by integer, float, character, extended grapheme cluster, and string
/// literals. The first step uses \c builtinProtocol while the second
/// step uses \c protocol.
///
/// \param literal The literal expression.
///
/// \param type The literal type. This type conforms to \c protocol,
/// and may also conform to \c builtinProtocol.
///
/// \param openedType The literal type as it was opened in the type system.
///
/// \param protocol The protocol that describes the literal requirement.
///
/// \param literalType Either the name of the associated type in
/// \c protocol that describes the argument type of the conversion function
/// (\c literalFuncName) or the argument type itself.
///
/// \param literalFuncName The name of the conversion function requirement
/// in \c protocol.
///
/// \param builtinProtocol The "builtin" form of the protocol, which
/// always takes builtin types and can only be properly implemented
/// by standard library types. If \c type does not conform to this
/// protocol, it's literal type will.
///
/// \param builtinLiteralType Either the name of the associated type in
/// \c builtinProtocol that describes the argument type of the builtin
/// conversion function (\c builtinLiteralFuncName) or the argument type
/// itself.
///
/// \param builtinLiteralFuncName The name of the conversion function
/// requirement in \c builtinProtocol.
///
/// \param isBuiltinArgType Function that determines whether the given
/// type is acceptable as the argument type for the builtin conversion.
///
/// \param brokenProtocolDiag The diagnostic to emit if the protocol
/// is broken.
///
/// \param brokenBuiltinProtocolDiag The diagnostic to emit if the builtin
/// protocol is broken.
///
/// \returns the converted literal expression.
Expr *convertLiteral(Expr *literal,
Type type,
Type openedType,
ProtocolDecl *protocol,
TypeOrName literalType,
Identifier literalFuncName,
ProtocolDecl *builtinProtocol,
TypeOrName builtinLiteralType,
Identifier builtinLiteralFuncName,
bool (*isBuiltinArgType)(Type),
Diag<> brokenProtocolDiag,
Diag<> brokenBuiltinProtocolDiag);
/// \brief Finish a function application by performing the appropriate
/// conversions on the function and argument expressions and setting
/// the resulting type.
///
/// \param apply The function application to finish type-checking, which
/// may be a newly-built expression.
///
/// \param openedType The "opened" type this expression had during
/// type checking, which will be used to specialize the resulting,
/// type-checked expression appropriately.
///
/// \param locator The locator for the original expression.
Expr *finishApply(ApplyExpr *apply, Type openedType,
ConstraintLocatorBuilder locator);
private:
/// \brief Retrieve the overload choice associated with the given
/// locator.
SelectedOverload getOverloadChoice(ConstraintLocator *locator) {
return *getOverloadChoiceIfAvailable(locator);
}
/// \brief Retrieve the overload choice associated with the given
/// locator.
Optional<SelectedOverload>
getOverloadChoiceIfAvailable(ConstraintLocator *locator) {
auto known = solution.overloadChoices.find(locator);
if (known != solution.overloadChoices.end())
return known->second;
return Nothing;
}
/// \brief Simplify the given type by substituting all occurrences of
/// type variables for their fixed types.
Type simplifyType(Type type) {
return solution.simplifyType(cs.getTypeChecker(), type);
}
public:
/// \brief Coerce the given expression to the given type.
///
/// This operation cannot fail.
///
/// \param expr The expression to coerce.
/// \param toType The type to coerce the expression to.
/// \param locator Locator used to describe where in this expression we are.
///
/// \returns the coerced expression, which will have type \c ToType.
Expr *coerceToType(Expr *expr, Type toType,
ConstraintLocatorBuilder locator);
/// \brief Coerce the given expression (which is the argument to a call) to
/// the given parameter type.
///
/// This operation cannot fail.
///
/// \param arg The argument expression.
/// \param paramType The parameter type.
/// \param locator Locator used to describe where in this expression we are.
///
/// \returns the coerced expression, which will have type \c ToType.
Expr *coerceCallArguments(Expr *arg, Type paramType,
ConstraintLocatorBuilder locator);
/// \brief Coerce the given object argument (e.g., for the base of a
/// member expression) to the given type.
///
/// \param expr The expression to coerce.
///
/// \param baseTy The base type
///
/// \param member The member being accessed.
///
/// \param IsDirectPropertyAccess True if this is a direct access to
/// computed properties that have storage.
///
/// \param locator Locator used to describe where in this expression we are.
Expr *coerceObjectArgumentToType(Expr *expr,
Type baseTy, ValueDecl *member,
bool IsDirectPropertyAccess,
ConstraintLocatorBuilder locator);
private:
/// \brief Build a new subscript.
///
/// \param base The base of the subscript.
/// \param index The index of the subscript.
/// \param locator The locator used to refer to the subscript.
Expr *buildSubscript(Expr *base, Expr *index,
ConstraintLocatorBuilder locator) {
// Determine the declaration selected for this subscript operation.
auto selected = getOverloadChoice(
cs.getConstraintLocator(
locator.withPathElement(
ConstraintLocator::SubscriptMember)));
auto choice = selected.choice;
auto subscript = cast<SubscriptDecl>(choice.getDecl());
auto &tc = cs.getTypeChecker();
auto baseTy = base->getType()->getRValueType();
// Check whether the base is 'super'.
bool isSuper = base->isSuperExpr();
// Handle accesses that implicitly look through ImplicitlyUnwrappedOptional<T>.
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(baseTy)) {
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy, locator);
if (!base) return nullptr;
}
// Figure out the index and result types.
auto containerTy
= subscript->getDeclContext()->getDeclaredTypeOfContext();
auto subscriptTy = simplifyType(selected.openedType);
auto indexTy = subscriptTy->castTo<AnyFunctionType>()->getInput();
auto resultTy = subscriptTy->castTo<AnyFunctionType>()->getResult();
// Coerce the index argument.
index = coerceCallArguments(index, indexTy,
locator.withPathElement(
ConstraintLocator::SubscriptIndex));
if (!index)
return nullptr;
// Form the subscript expression.
// Handle dynamic lookup.
if (selected.choice.getKind() == OverloadChoiceKind::DeclViaDynamic ||
subscript->getAttrs().hasAttribute<OptionalAttr>()) {
// If we've found an optional method in a protocol, the base type is
// AnyObject.
if (selected.choice.getKind() != OverloadChoiceKind::DeclViaDynamic) {
auto proto = tc.getProtocol(index->getStartLoc(),
KnownProtocolKind::AnyObject);
if (!proto)
return nullptr;
baseTy = proto->getDeclaredType();
}
base = coerceObjectArgumentToType(base, baseTy, subscript, false,
locator);
if (!base)
return nullptr;
auto subscriptExpr = new (tc.Context) DynamicSubscriptExpr(base,
index,
subscript);
subscriptExpr->setType(resultTy);
return subscriptExpr;
}
// Handle subscripting of generics.
if (subscript->getDeclContext()->isGenericContext()) {
auto dc = subscript->getDeclContext();
// Compute the substitutions used to reference the subscript.
SmallVector<Substitution, 4> substitutions;
solution.computeSubstitutions(subscript->getInterfaceType(),
dc,
selected.openedFullType,
substitutions);
// Convert the base.
auto openedFullFnType = selected.openedFullType->castTo<FunctionType>();
auto openedBaseType = openedFullFnType->getInput();
containerTy = solution.simplifyType(tc, openedBaseType);
base = coerceObjectArgumentToType(base, containerTy, subscript, false,
locator);
locator.withPathElement(ConstraintLocator::MemberRefBase);
if (!base)
return nullptr;
// Form the generic subscript expression.
auto subscriptExpr
= new (tc.Context) SubscriptExpr(base, index,
ConcreteDeclRef(tc.Context,
subscript,
substitutions));
subscriptExpr->setType(resultTy);
subscriptExpr->setIsSuper(isSuper);
return subscriptExpr;
}
Type selfTy = containerTy;
if (selfTy->isEqual(baseTy) && !selfTy->hasReferenceSemantics())
if (base->getType()->is<LValueType>())
selfTy = InOutType::get(selfTy);
// Coerce the base to the container type.
base = coerceObjectArgumentToType(base, selfTy, subscript, false,
locator);
if (!base)
return nullptr;
// Form a normal subscript.
auto *subscriptExpr
= new (tc.Context) SubscriptExpr(base, index, subscript);
subscriptExpr->setType(resultTy);
subscriptExpr->setIsSuper(isSuper);
return subscriptExpr;
}
/// \brief Build a new reference to another constructor.
Expr *buildOtherConstructorRef(Type openedFullType,
ConstructorDecl *ctor, SourceLoc loc,
bool implicit) {
auto &tc = cs.getTypeChecker();
auto &ctx = tc.Context;
// Compute the concrete reference.
ConcreteDeclRef ref;
Type resultTy;
if (ctor->getInterfaceType()->is<GenericFunctionType>()) {
// Compute the reference to the generic constructor.
SmallVector<Substitution, 4> substitutions;
resultTy = solution.computeSubstitutions(
ctor->getInterfaceType(),
ctor,
openedFullType,
substitutions);
ref = ConcreteDeclRef(ctx, ctor, substitutions);
// The constructor was opened with the allocating type, not the
// initializer type. Map the former into the latter.
auto resultFnTy = resultTy->castTo<FunctionType>();
auto selfTy = resultFnTy->getInput()->getRValueInstanceType();
if (!selfTy->hasReferenceSemantics())
selfTy = InOutType::get(selfTy);
resultTy = FunctionType::get(selfTy, resultFnTy->getResult(),
resultFnTy->getExtInfo());
} else {
ref = ConcreteDeclRef(ctor);
resultTy = ctor->getInitializerType();
}
// Build the constructor reference.
Expr *refExpr = new (ctx) OtherConstructorDeclRefExpr(ref, loc, implicit,
resultTy);
return refExpr;
}
/// Bridge the given value to its corresponding Objective-C object
/// type.
///
/// This routine should only be used for bridging value types.
///
/// \param value The value to be bridged.
Expr *bridgeToObjectiveC(Expr *value) {
auto &tc = cs.getTypeChecker();
// Find the _BridgedToObjectiveC protocol.
auto bridgedProto
= tc.Context.getProtocol(KnownProtocolKind::_BridgedToObjectiveCType);
// Find the conformance of the value type to _BridgedToObjectiveC.
Type valueType = value->getType()->getRValueType();
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(valueType, bridgedProto, cs.DC,
&conformance);
assert(conforms && "Should already have checked the conformance");
(void)conforms;
// Form the call.
return tc.callWitness(value, cs.DC, bridgedProto,
conformance,
tc.Context.Id_bridgeToObjectiveC,
{ }, diag::broken_bridged_to_objc_protocol);
}
/// Bridge the given object from Objective-C to its value type.
///
/// This routine should only be used for bridging value types.
///
/// \param object The object, whose type should already be of the type
/// that the value type bridges through.
///
/// \param valueType The value type to which we are bridging.
///
/// \returns a value of type \c valueType that stores the bridged result.
Expr *bridgeFromObjectiveC(Expr *object, Type valueType) {
auto &tc = cs.getTypeChecker();
// Find the _BridgedToObjectiveC protocol.
auto bridgedProto
= tc.Context.getProtocol(KnownProtocolKind::_BridgedToObjectiveCType);
// Find the conformance of the value type to _BridgedToObjectiveC.
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(valueType, bridgedProto, cs.DC,
&conformance);
assert(conforms && "Should already have checked the conformance");
(void)conforms;
// Form the call.
return tc.callWitness(TypeExpr::createImplicit(valueType, tc.Context),
cs.DC, bridgedProto, conformance,
tc.Context.Id_bridgeFromObjectiveC,
{ object },
diag::broken_bridged_to_objc_protocol);
}
/// Conditionally bridge the given object from Objective-C to its
/// value type.
///
/// This routine should only be used for bridging value types.
///
/// \param object The object, whose type should already be of the type
/// that the value type bridges through.
///
/// \param valueType The value type to which we are bridging.
///
/// \returns a value of type \c valueType? that stores the bridged result.
Expr *bridgeFromObjectiveCConditional(Expr *object, Type valueType) {
auto &tc = cs.getTypeChecker();
// Find the _ConditionallyBridgedToObjectiveC protocol.
auto conditionalBridgedProto
= tc.Context.getProtocol(
KnownProtocolKind::_ConditionallyBridgedToObjectiveCType);
// Check whether the value type conforms to
// _ConditionallyBridgedToObjectiveC. If so, we have a specific
// entry point for conditional bridging.
ProtocolConformance *conditionalConformance = nullptr;
if (tc.conformsToProtocol(valueType, conditionalBridgedProto, cs.DC,
&conditionalConformance)) {
Expr *valueMetatype = TypeExpr::createImplicit(valueType, tc.Context);
Expr *args[1] = { object };
return tc.callWitness(valueMetatype, cs.DC, conditionalBridgedProto,
conditionalConformance,
tc.Context.Id_bridgeFromObjectiveCConditional,
args, diag::broken_bridged_to_objc_protocol);
}
Expr *result = bridgeFromObjectiveC(object, valueType);
if (!result)
return nullptr;
return new (tc.Context) InjectIntoOptionalExpr(
result,
OptionalType::get(result->getType()));
}
TypeAliasDecl *MaxIntegerTypeDecl = nullptr;
TypeAliasDecl *MaxFloatTypeDecl = nullptr;
public:
ExprRewriter(ConstraintSystem &cs, const Solution &solution)
: cs(cs), dc(cs.DC), solution(solution) { }
~ExprRewriter() {
finalize();
}
ConstraintSystem &getConstraintSystem() const { return cs; }
/// \brief Simplify the expression type and return the expression.
///
/// This routine is used for 'simple' expressions that only need their
/// types simplified, with no further computation.
Expr *simplifyExprType(Expr *expr) {
auto toType = simplifyType(expr->getType());
expr->setType(toType);
return expr;
}
Expr *visitErrorExpr(ErrorExpr *expr) {
// Do nothing with error expressions.
return expr;
}
Expr *handleIntegerLiteralExpr(LiteralExpr *expr) {
auto &tc = cs.getTypeChecker();
ProtocolDecl *protocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::IntegerLiteralConvertible);
ProtocolDecl *builtinProtocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::_BuiltinIntegerLiteralConvertible);
// For type-sugar reasons, prefer the spelling of the default literal
// type.
auto type = simplifyType(expr->getType());
if (auto defaultType = tc.getDefaultType(protocol, dc)) {
if (defaultType->isEqual(type))
type = defaultType;
}
if (auto floatProtocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::FloatLiteralConvertible)) {
if (auto defaultFloatType = tc.getDefaultType(floatProtocol, dc)) {
if (defaultFloatType->isEqual(type))
type = defaultFloatType;
}
}
// Find the maximum-sized builtin integer type.
if(!MaxIntegerTypeDecl) {
UnqualifiedLookup lookup(tc.Context.Id_MaxBuiltinIntegerType,
tc.getStdlibModule(dc),
&tc);
MaxIntegerTypeDecl =
dyn_cast_or_null<TypeAliasDecl>(lookup.getSingleTypeResult());
}
if (!MaxIntegerTypeDecl ||
!MaxIntegerTypeDecl->getUnderlyingType()->is<BuiltinIntegerType>()) {
tc.diagnose(expr->getLoc(), diag::no_MaxBuiltinIntegerType_found);
return nullptr;
}
auto maxType = MaxIntegerTypeDecl->getUnderlyingType();
return convertLiteral(
expr,
type,
expr->getType(),
protocol,
tc.Context.Id_IntegerLiteralType,
tc.Context.Id_ConvertFromIntegerLiteral,
builtinProtocol,
maxType,
tc.Context.Id_ConvertFromBuiltinIntegerLiteral,
nullptr,
diag::integer_literal_broken_proto,
diag::builtin_integer_literal_broken_proto);
}
Expr *visitNilLiteralExpr(NilLiteralExpr *expr) {
auto &tc = cs.getTypeChecker();
auto *protocol = tc.getProtocol(expr->getLoc(),
KnownProtocolKind::NilLiteralConvertible);
// For type-sugar reasons, prefer the spelling of the default literal
// type.
auto type = simplifyType(expr->getType());
if (auto defaultType = tc.getDefaultType(protocol, dc)) {
if (defaultType->isEqual(type))
type = defaultType;
}
return convertLiteral(expr, type, expr->getType(), protocol,
Identifier(), tc.Context.Id_ConvertFromNilLiteral,
nullptr, Identifier(),
Identifier(),
[] (Type type) -> bool {
return false;
},
diag::nil_literal_broken_proto,
diag::nil_literal_broken_proto);
}
Expr *visitIntegerLiteralExpr(IntegerLiteralExpr *expr) {
return handleIntegerLiteralExpr(expr);
}
Expr *visitFloatLiteralExpr(FloatLiteralExpr *expr) {
auto &tc = cs.getTypeChecker();
ProtocolDecl *protocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::FloatLiteralConvertible);
ProtocolDecl *builtinProtocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::_BuiltinFloatLiteralConvertible);
// For type-sugar reasons, prefer the spelling of the default literal
// type.
auto type = simplifyType(expr->getType());
if (auto defaultType = tc.getDefaultType(protocol, dc)) {
if (defaultType->isEqual(type))
type = defaultType;
}
// Find the maximum-sized builtin float type.
// FIXME: Cache name lookup.
if (!MaxFloatTypeDecl) {
UnqualifiedLookup lookup(tc.Context.Id_MaxBuiltinFloatType,
tc.getStdlibModule(dc),
&tc);
MaxFloatTypeDecl =
dyn_cast_or_null<TypeAliasDecl>(lookup.getSingleTypeResult());
}
if (!MaxFloatTypeDecl ||
!MaxFloatTypeDecl->getUnderlyingType()->is<BuiltinFloatType>()) {
tc.diagnose(expr->getLoc(), diag::no_MaxBuiltinFloatType_found);
return nullptr;
}
auto maxType = MaxFloatTypeDecl->getUnderlyingType();
return convertLiteral(
expr,
type,
expr->getType(),
protocol,
tc.Context.Id_FloatLiteralType,
tc.Context.Id_ConvertFromFloatLiteral,
builtinProtocol,
maxType,
tc.Context.Id_ConvertFromBuiltinFloatLiteral,
nullptr,
diag::float_literal_broken_proto,
diag::builtin_float_literal_broken_proto);
}
Expr *visitBooleanLiteralExpr(BooleanLiteralExpr *expr) {
auto &tc = cs.getTypeChecker();
ProtocolDecl *protocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::BooleanLiteralConvertible);
ProtocolDecl *builtinProtocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::_BuiltinBooleanLiteralConvertible);
if (!protocol || !builtinProtocol)
return nullptr;
auto type = simplifyType(expr->getType());
return convertLiteral(
expr,
type,
expr->getType(),
protocol,
tc.Context.Id_BooleanLiteralType,
tc.Context.Id_ConvertFromBooleanLiteral,
builtinProtocol,
Type(BuiltinIntegerType::get(BuiltinIntegerWidth::fixed(1),
tc.Context)),
tc.Context.Id_ConvertFromBuiltinBooleanLiteral,
nullptr,
diag::boolean_literal_broken_proto,
diag::builtin_boolean_literal_broken_proto);
}
Expr *visitCharacterLiteralExpr(CharacterLiteralExpr *expr) {
auto &tc = cs.getTypeChecker();
ProtocolDecl *protocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::CharacterLiteralConvertible);
ProtocolDecl *builtinProtocol
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::_BuiltinCharacterLiteralConvertible);
// For type-sugar reasons, prefer the spelling of the default literal
// type.
auto type = simplifyType(expr->getType());
if (auto defaultType = tc.getDefaultType(protocol, dc)) {
if (defaultType->isEqual(type))
type = defaultType;
}
return convertLiteral(
expr,
type,
expr->getType(),
protocol,
tc.Context.Id_CharacterLiteralType,
tc.Context.Id_ConvertFromCharacterLiteral,
builtinProtocol,
Type(BuiltinIntegerType::get(32, tc.Context)),
tc.Context.Id_ConvertFromBuiltinCharacterLiteral,
[] (Type type) -> bool {
if (auto builtinInt = type->getAs<BuiltinIntegerType>()) {
return builtinInt->isFixedWidth(32);
}
return false;
},
diag::character_literal_broken_proto,
diag::builtin_character_literal_broken_proto);
}
Expr *handleStringLiteralExpr(LiteralExpr *expr) {
auto stringLiteral = dyn_cast<StringLiteralExpr>(expr);
auto magicLiteral = dyn_cast<MagicIdentifierLiteralExpr>(expr);
assert(bool(stringLiteral) != bool(magicLiteral) &&
"literal must be either a string literal or a magic literal");
auto type = simplifyType(expr->getType());
auto &tc = cs.getTypeChecker();
bool isStringLiteral = true;
ProtocolDecl *protocol = tc.getProtocol(
expr->getLoc(), KnownProtocolKind::StringLiteralConvertible);
if (!tc.conformsToProtocol(type, protocol, cs.DC)) {
// If the type does not conform to StringLiteralConvertible, it should
// be ExtendedGraphemeClusterLiteralConvertible.
protocol = tc.getProtocol(
expr->getLoc(),
KnownProtocolKind::ExtendedGraphemeClusterLiteralConvertible);
isStringLiteral = false;
}
assert(tc.conformsToProtocol(type, protocol, cs.DC));
// For type-sugar reasons, prefer the spelling of the default literal
// type.
if (auto defaultType = tc.getDefaultType(protocol, dc)) {
if (defaultType->isEqual(type))
type = defaultType;
}
// Add the first element (
SmallVector<TupleTypeElt, 3> elements;
elements.push_back(TupleTypeElt(tc.Context.TheRawPointerType));
/*
TupleTypeElt(BuiltinIntegerType::getWordType(tc.Context)),
TupleTypeElt(BuiltinIntegerType::get(1, tc.Context))
*/
ProtocolDecl *builtinProtocol;
Identifier literalType;
Identifier literalFuncName;
Identifier builtinLiteralFuncName;
Diag<> brokenProtocolDiag;
Diag<> brokenBuiltinProtocolDiag;
if (isStringLiteral) {
literalType = tc.Context.Id_StringLiteralType;
literalFuncName = tc.Context.Id_ConvertFromStringLiteral;
// If the type can handle UTF-16 string literals, prefer them.
builtinProtocol = tc.getProtocol(
expr->getLoc(),
KnownProtocolKind::_BuiltinUTF16StringLiteralConvertible);
if (tc.conformsToProtocol(type, builtinProtocol, cs.DC)) {
builtinLiteralFuncName =
tc.Context.Id_ConvertFromBuiltinUTF16StringLiteral;
elements.push_back(
TupleTypeElt(BuiltinIntegerType::getWordType(tc.Context),
tc.Context.getIdentifier("numberOfCodeUnits")));
if (stringLiteral)
stringLiteral->setEncoding(StringLiteralExpr::UTF16);
else
magicLiteral->setStringEncoding(StringLiteralExpr::UTF16);
} else {
// Otherwise, fall back to UTF-8.
builtinProtocol = tc.getProtocol(
expr->getLoc(),
KnownProtocolKind::_BuiltinStringLiteralConvertible);
builtinLiteralFuncName =
tc.Context.Id_ConvertFromBuiltinStringLiteral;
elements.push_back(
TupleTypeElt(BuiltinIntegerType::getWordType(tc.Context),
tc.Context.getIdentifier("byteSize")));
elements.push_back(
TupleTypeElt(BuiltinIntegerType::get(1, tc.Context),
tc.Context.getIdentifier("isASCII")));
if (stringLiteral)
stringLiteral->setEncoding(StringLiteralExpr::UTF8);
else
magicLiteral->setStringEncoding(StringLiteralExpr::UTF8);
}
brokenProtocolDiag = diag::string_literal_broken_proto;
brokenBuiltinProtocolDiag = diag::builtin_string_literal_broken_proto;
} else {
literalType = tc.Context.Id_ExtendedGraphemeClusterLiteralType;
literalFuncName =
tc.Context.Id_ConvertFromExtendedGraphemeClusterLiteral;
builtinLiteralFuncName =
tc.Context.Id_ConvertFromBuiltinExtendedGraphemeClusterLiteral;
builtinProtocol = tc.getProtocol(
expr->getLoc(),
KnownProtocolKind::_BuiltinExtendedGraphemeClusterLiteralConvertible);
elements.push_back(
TupleTypeElt(BuiltinIntegerType::getWordType(tc.Context),
tc.Context.getIdentifier("byteSize")));
elements.push_back(
TupleTypeElt(BuiltinIntegerType::get(1, tc.Context),
tc.Context.getIdentifier("isASCII")));
brokenProtocolDiag =
diag::extended_grapheme_cluster_literal_broken_proto;
brokenBuiltinProtocolDiag =
diag::builtin_extended_grapheme_cluster_literal_broken_proto;
}
return convertLiteral(expr,
type,
expr->getType(),
protocol,
literalType,
literalFuncName,
builtinProtocol,
TupleType::get(elements, tc.Context),
builtinLiteralFuncName,
nullptr,
brokenProtocolDiag,
brokenBuiltinProtocolDiag);
}
Expr *visitStringLiteralExpr(StringLiteralExpr *expr) {
return handleStringLiteralExpr(expr);
}
Expr *
visitInterpolatedStringLiteralExpr(InterpolatedStringLiteralExpr *expr) {
// Figure out the string type we're converting to.
auto openedType = expr->getType();
auto type = simplifyType(openedType);
expr->setType(type);
// Find the string interpolation protocol we need.
auto &tc = cs.getTypeChecker();
auto &C = tc.Context;
auto interpolationProto
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::StringInterpolationConvertible);
assert(interpolationProto && "Missing string interpolation protocol?");
// FIXME: Cache name,
auto member =
findNamedWitness(tc, dc, type, interpolationProto,
C.Id_ConvertFromStringInterpolation,
diag::interpolation_broken_proto);
auto segmentMember =
findNamedWitness(tc, dc, type, interpolationProto,
C.Id_ConvertFromStringInterpolationSegment,
diag::interpolation_broken_proto);
if (!member || !segmentMember)
return nullptr;
// Build a reference to the convertFromStringInterpolation member.
// FIXME: This location info is bogus.
auto typeRef = TypeExpr::createImplicitHack(expr->getStartLoc(),
type, tc.Context);
Expr *memberRef = new (tc.Context) MemberRefExpr(typeRef,
expr->getStartLoc(),
member,
expr->getStartLoc(),
/*Implicit=*/true);
bool failed = tc.typeCheckExpressionShallow(memberRef, cs.DC);
assert(!failed && "Could not reference string interpolation witness");
(void)failed;
// Create a tuple containing all of the segments.
SmallVector<Expr *, 4> segments;
unsigned index = 0;
ConstraintLocatorBuilder locatorBuilder(cs.getConstraintLocator(expr));
for (auto segment : expr->getSegments()) {
auto locator = cs.getConstraintLocator(
locatorBuilder.withPathElement(
LocatorPathElt::getInterpolationArgument(index++)));
// Find the conversion method we chose.
auto choice = getOverloadChoice(locator);
auto memberRef = buildMemberRef(
typeRef, choice.openedFullType,
segment->getStartLoc(), choice.choice.getDecl(),
segment->getStartLoc(), choice.openedType,
locatorBuilder, /*Implicit=*/true, /*directPropertyAccess=*/false);
ApplyExpr *apply =
new (tc.Context) CallExpr(memberRef, segment, /*Implicit=*/true);
segment = finishApply(apply, openedType, locatorBuilder);
segments.push_back(segment);
}
Expr *argument = nullptr;
if (segments.size() == 1)
argument = segments.front();
else {
SmallVector<TupleTypeElt, 4> tupleElements(segments.size(),
TupleTypeElt(type));
argument = TupleExpr::create(tc.Context,
expr->getStartLoc(),
segments,
{ },
{ },
expr->getStartLoc(),
/*hasTrailingClosure=*/false,
/*Implicit=*/true,
TupleType::get(tupleElements,tc.Context));
}
// Call the convertFromStringInterpolation member with the arguments.
ApplyExpr *apply = new (tc.Context) CallExpr(memberRef, argument,
/*Implicit=*/true);
expr->setSemanticExpr(finishApply(apply, openedType, locatorBuilder));
return expr;
}
Expr *visitMagicIdentifierLiteralExpr(MagicIdentifierLiteralExpr *expr) {
switch (expr->getKind()) {
case MagicIdentifierLiteralExpr::File:
case MagicIdentifierLiteralExpr::Function:
return handleStringLiteralExpr(expr);
case MagicIdentifierLiteralExpr::Line:
case MagicIdentifierLiteralExpr::Column:
return handleIntegerLiteralExpr(expr);
}
}
/// \brief Retrieve the type of a reference to the given declaration.
Type getTypeOfDeclReference(ValueDecl *decl, bool isSpecialized) {
if (auto typeDecl = dyn_cast<TypeDecl>(decl)) {
// Resolve the reference to this type declaration in our
// current context.
auto type = cs.getTypeChecker().resolveTypeInContext(typeDecl, dc,
isSpecialized);
if (!type)
return nullptr;
// Refer to the metatype of this type.
return MetatypeType::get(type);
}
return cs.TC.getUnopenedTypeOfReference(decl, Type(), dc,
/*wantInterfaceType=*/true);
}
Expr *visitDeclRefExpr(DeclRefExpr *expr) {
auto locator = cs.getConstraintLocator(expr);
// Find the overload choice used for this declaration reference.
auto selected = getOverloadChoice(locator);
auto choice = selected.choice;
auto decl = choice.getDecl();
// FIXME: Cannibalize the existing DeclRefExpr rather than allocating a
// new one?
return buildDeclRef(decl, expr->getLoc(), selected.openedFullType,
locator, expr->isSpecialized(), expr->isImplicit(),
expr->isDirectPropertyAccess());
}
Expr *visitSuperRefExpr(SuperRefExpr *expr) {
simplifyExprType(expr);
return expr;
}
Expr *visitTypeExpr(TypeExpr *expr) {
auto toType = simplifyType(expr->getTypeLoc().getType());
expr->getTypeLoc().setType(toType, /*validated=*/true);
expr->setType(MetatypeType::get(toType));
return expr;
}
Expr *visitOtherConstructorDeclRefExpr(OtherConstructorDeclRefExpr *expr) {
expr->setType(expr->getDecl()->getInitializerType());
return expr;
}
Expr *visitUnresolvedConstructorExpr(UnresolvedConstructorExpr *expr) {
// Resolve the callee to the constructor declaration selected.
auto selected = getOverloadChoice(
cs.getConstraintLocator(
expr,
ConstraintLocator::ConstructorMember));
auto choice = selected.choice;
auto *ctor = cast<ConstructorDecl>(choice.getDecl());
auto arg = expr->getSubExpr()->getSemanticsProvidingExpr();
auto &tc = cs.getTypeChecker();
// If the subexpression is a metatype, build a direct reference to the
// constructor.
if (arg->getType()->is<AnyMetatypeType>()) {
return buildMemberRef(expr->getSubExpr(),
selected.openedFullType,
expr->getDotLoc(),
ctor,
expr->getConstructorLoc(),
expr->getType(),
ConstraintLocatorBuilder(
cs.getConstraintLocator(expr)),
expr->isImplicit(),
/*IsDirectPropertyAccess=*/false);
}
// The subexpression must be either 'self' or 'super'.
if (!arg->isSuperExpr()) {
// 'super' references have already been fully checked; handle the
// 'self' case below.
bool diagnoseBadInitRef = true;
if (auto dre = dyn_cast<DeclRefExpr>(arg)) {
if (dre->getDecl()->getName() == cs.getASTContext().Id_self) {
// We have a reference to 'self'.
diagnoseBadInitRef = false;
// Make sure the reference to 'self' occurs within an initializer.
if (!dyn_cast_or_null<ConstructorDecl>(
cs.DC->getInnermostMethodContext())) {
tc.diagnose(expr->getDotLoc(),
diag::init_delegation_outside_initializer);
}
}
}
// If we need to diagnose this as a bad reference to an initializer,
// do so now.
if (diagnoseBadInitRef) {
// Determine whether 'super' would have made sense as a base.
bool hasSuper = false;
if (auto func = cs.DC->getInnermostMethodContext()) {
if (auto nominalType
= func->getDeclContext()->getDeclaredTypeOfContext()) {
if (auto classDecl = nominalType->getClassOrBoundGenericClass()) {
hasSuper = classDecl->hasSuperclass();
}
}
}
tc.diagnose(expr->getDotLoc(), diag::bad_init_ref_base, hasSuper);
}
}
// Build a partial application of the initializer.
Expr *ctorRef = buildOtherConstructorRef(selected.openedFullType,
ctor, expr->getConstructorLoc(),
expr->isImplicit());
auto *call
= new (cs.getASTContext()) DotSyntaxCallExpr(ctorRef,
expr->getDotLoc(),
expr->getSubExpr());
return finishApply(call, expr->getType(),
ConstraintLocatorBuilder(
cs.getConstraintLocator(expr)));
}
Expr *visitDotSyntaxBaseIgnoredExpr(DotSyntaxBaseIgnoredExpr *expr) {
return simplifyExprType(expr);
}
Expr *visitOverloadedDeclRefExpr(OverloadedDeclRefExpr *expr) {
// Determine the declaration selected for this overloaded reference.
auto locator = cs.getConstraintLocator(expr);
auto selected = getOverloadChoice(locator);
auto choice = selected.choice;
auto decl = choice.getDecl();
return buildDeclRef(decl, expr->getLoc(), selected.openedFullType,
locator, expr->isSpecialized(), expr->isImplicit(),
/*isDirectPropertyAccess*/false);
}
Expr *visitOverloadedMemberRefExpr(OverloadedMemberRefExpr *expr) {
auto selected = getOverloadChoice(
cs.getConstraintLocator(expr,
ConstraintLocator::Member));
return buildMemberRef(expr->getBase(),
selected.openedFullType,
expr->getDotLoc(),
selected.choice.getDecl(), expr->getMemberLoc(),
selected.openedType,
cs.getConstraintLocator(expr),
expr->isImplicit(), /*direct ivar*/false);
}
Expr *visitUnresolvedDeclRefExpr(UnresolvedDeclRefExpr *expr) {
// FIXME: We should have generated an overload set from this, in which
// case we can emit a typo-correction error here but recover well.
return nullptr;
}
Expr *visitUnresolvedSpecializeExpr(UnresolvedSpecializeExpr *expr) {
// Our specializations should have resolved the subexpr to the right type.
if (auto DRE = dyn_cast<DeclRefExpr>(expr->getSubExpr())) {
assert(DRE->getGenericArgs().empty() ||
DRE->getGenericArgs().size() == expr->getUnresolvedParams().size());
if (DRE->getGenericArgs().empty()) {
SmallVector<TypeRepr *, 8> GenArgs;
for (auto TL : expr->getUnresolvedParams())
GenArgs.push_back(TL.getTypeRepr());
DRE->setGenericArgs(GenArgs);
}
}
return expr->getSubExpr();
}
Expr *visitMemberRefExpr(MemberRefExpr *expr) {
auto selected = getOverloadChoice(
cs.getConstraintLocator(expr,
ConstraintLocator::Member));
return buildMemberRef(expr->getBase(),
selected.openedFullType,
expr->getDotLoc(),
selected.choice.getDecl(), expr->getNameLoc(),
selected.openedType,
cs.getConstraintLocator(expr),
expr->isImplicit(),
expr->isDirectPropertyAccess());
}
Expr *visitDynamicMemberRefExpr(DynamicMemberRefExpr *expr) {
auto selected = getOverloadChoice(
cs.getConstraintLocator(expr,
ConstraintLocator::Member));
return buildDynamicMemberRef(expr->getBase(), expr->getDotLoc(),
selected.choice.getDecl(),
expr->getNameLoc(),
selected.openedType,
cs.getConstraintLocator(expr));
}
Expr *visitUnresolvedMemberExpr(UnresolvedMemberExpr *expr) {
// Dig out the type of the base, which will be the result
// type of this expression.
Type baseTy = simplifyType(expr->getType())->getRValueType();
auto &tc = cs.getTypeChecker();
// Find the selected member.
auto selected = getOverloadChoice(
cs.getConstraintLocator(
expr, ConstraintLocator::UnresolvedMember));
auto member = selected.choice.getDecl();
// If the member came by optional unwrapping, then unwrap the base type.
if (selected.choice.getKind()
== OverloadChoiceKind::DeclViaUnwrappedOptional) {
baseTy = baseTy->getAnyOptionalObjectType();
assert(baseTy
&& "got unwrapped optional decl from non-optional base?!");
}
// The base expression is simply the metatype of the base type.
// FIXME: This location info is bogus.
auto base = TypeExpr::createImplicitHack(expr->getDotLoc(),
baseTy, tc.Context);
// Build the member reference.
auto result = buildMemberRef(base,
selected.openedFullType,
expr->getDotLoc(), member,
expr->getNameLoc(),
selected.openedType,
cs.getConstraintLocator(expr),
expr->isImplicit(), /*direct ivar*/false);
if (!result)
return nullptr;
// If there was an argument, apply it.
if (auto arg = expr->getArgument()) {
ApplyExpr *apply = new (tc.Context) CallExpr(result, arg,
/*Implicit=*/false);
result = finishApply(apply, Type(), cs.getConstraintLocator(expr));
}
return result;
}
private:
struct MemberPartialApplication {
unsigned level : 31;
// Selector for the partial_application_of_method_invalid diagnostic
// message.
enum : unsigned {
Struct,
Enum,
Archetype,
Protocol
};
unsigned kind : 3;
};
// A map used to track partial applications of methods to require that they
// be fully applied. Partial applications of value types would capture
// 'self' as an inout and hide any mutation of 'self', which is surprising.
llvm::SmallDenseMap<Expr*, MemberPartialApplication, 2>
InvalidPartialApplications;
/// A list of "suspicious" optional injections that come from
/// forced downcasts.
SmallVector<InjectIntoOptionalExpr *, 4> SuspiciousOptionalInjections;
public:
/// A list of optional injections that have been diagnosed.
llvm::SmallPtrSet<InjectIntoOptionalExpr *, 4> DiagnosedOptionalInjections;
private:
Expr *applyMemberRefExpr(Expr *expr,
Expr *base,
SourceLoc dotLoc,
SourceLoc nameLoc,
bool implicit) {
// Determine the declaration selected for this overloaded reference.
auto selected = getOverloadChoice(
cs.getConstraintLocator(
expr,
ConstraintLocator::MemberRefBase));
switch (selected.choice.getKind()) {
case OverloadChoiceKind::DeclViaBridge: {
// Look through an implicitly unwrapped optional.
auto baseTy = base->getType()->getRValueType();
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(baseTy)){
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy,
cs.getConstraintLocator(base));
if (!base) return nullptr;
baseTy = base->getType()->getRValueType();
}
if (auto baseMetaTy = baseTy->getAs<MetatypeType>()) {
auto &tc = cs.getTypeChecker();
auto classTy = tc.getBridgedToObjC(cs.DC,
baseMetaTy->getInstanceType());
// FIXME: We're dropping side effects in the base here!
base = TypeExpr::createImplicitHack(base->getLoc(), classTy,
tc.Context);
} else {
// Bridge the base to its corresponding Objective-C object.
base = bridgeToObjectiveC(base);
}
// Fall through to build the member reference.
SWIFT_FALLTHROUGH;
}
case OverloadChoiceKind::Decl:
case OverloadChoiceKind::DeclViaUnwrappedOptional: {
auto member = buildMemberRef(base,
selected.openedFullType,
dotLoc,
selected.choice.getDecl(),
nameLoc,
selected.openedType,
cs.getConstraintLocator(expr),
implicit, /*direct ivar*/false);
// If this is an application of a value type method, arrange for us to
// check that it gets fully applied.
FuncDecl *fn = nullptr;
Optional<unsigned> kind;
if (auto apply = dyn_cast<ApplyExpr>(member)) {
auto selfTy = apply->getArg()->getType()->getRValueType();
auto fnDeclRef = dyn_cast<DeclRefExpr>(apply->getFn());
if (!fnDeclRef)
goto not_value_type_member;
fn = dyn_cast<FuncDecl>(fnDeclRef->getDecl());
if (selfTy->getStructOrBoundGenericStruct())
kind = MemberPartialApplication::Struct;
else if (selfTy->getEnumOrBoundGenericEnum())
kind = MemberPartialApplication::Enum;
else
goto not_value_type_member;
} else if (auto pmRef = dyn_cast<MemberRefExpr>(member)) {
auto baseTy = pmRef->getBase()->getType();
if (baseTy->hasReferenceSemantics())
goto not_value_type_member;
if (baseTy->isAnyExistentialType()) {
kind = MemberPartialApplication::Protocol;
} else if (isa<FuncDecl>(pmRef->getMember().getDecl()))
kind = MemberPartialApplication::Archetype;
else
goto not_value_type_member;
fn = dyn_cast<FuncDecl>(pmRef->getMember().getDecl());
}
if (!fn)
goto not_value_type_member;
if (fn->isInstanceMember())
InvalidPartialApplications.insert({
member,
// We need to apply all of the non-self argument clauses.
{fn->getNaturalArgumentCount() - 1, kind.getValue() },
});
not_value_type_member:
return member;
}
case OverloadChoiceKind::DeclViaDynamic:
return buildDynamicMemberRef(base, dotLoc,
selected.choice.getDecl(),
nameLoc,
selected.openedType,
cs.getConstraintLocator(expr));
case OverloadChoiceKind::TupleIndex: {
auto baseTy = base->getType()->getRValueType();
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(baseTy)) {
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy,
cs.getConstraintLocator(base));
if (!base) return nullptr;
}
return new (cs.getASTContext()) TupleElementExpr(
base,
dotLoc,
selected.choice.getTupleIndex(),
nameLoc,
simplifyType(expr->getType()));
}
case OverloadChoiceKind::BaseType: {
// FIXME: Losing ".0" sugar here.
return base;
}
case OverloadChoiceKind::TypeDecl:
llvm_unreachable("Nonsensical overload choice");
}
}
public:
Expr *visitUnresolvedSelectorExpr(UnresolvedSelectorExpr *expr) {
return applyMemberRefExpr(expr, expr->getBase(), expr->getDotLoc(),
expr->getNameRange().Start,
expr->isImplicit());
llvm_unreachable("not implemented");
}
Expr *visitUnresolvedDotExpr(UnresolvedDotExpr *expr) {
return applyMemberRefExpr(expr, expr->getBase(), expr->getDotLoc(),
expr->getNameLoc(), expr->isImplicit());
}
Expr *visitSequenceExpr(SequenceExpr *expr) {
llvm_unreachable("Expression wasn't parsed?");
}
Expr *visitIdentityExpr(IdentityExpr *expr) {
expr->setType(expr->getSubExpr()->getType());
return expr;
}
Expr *visitParenExpr(ParenExpr *expr) {
auto &ctx = cs.getASTContext();
expr->setType(ParenType::get(ctx, expr->getSubExpr()->getType()));
return expr;
}
Expr *visitTupleExpr(TupleExpr *expr) {
return simplifyExprType(expr);
}
Expr *visitSubscriptExpr(SubscriptExpr *expr) {
return buildSubscript(expr->getBase(), expr->getIndex(),
cs.getConstraintLocator(expr));
}
Expr *visitArrayExpr(ArrayExpr *expr) {
Type openedType = expr->getType();
Type arrayTy = simplifyType(openedType);
auto &tc = cs.getTypeChecker();
ProtocolDecl *arrayProto
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::ArrayLiteralConvertible);
assert(arrayProto && "type-checked array literal w/o protocol?!");
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(arrayTy, arrayProto,
cs.DC, &conformance);
(void)conforms;
assert(conforms && "Type does not conform to protocol?");
// Call the witness that builds the array literal.
// FIXME: callWitness() may end up re-doing some work we already did
// to convert the array literal elements to the element type. It would
// be nicer to re-use them.
// FIXME: Cache the name.
// FIXME: This location info is bogus.
Expr *typeRef = TypeExpr::createImplicitHack(expr->getLoc(),
arrayTy, tc.Context);
auto name = tc.Context.Id_ConvertFromArrayLiteral;
auto arg = expr->getSubExpr();
Expr *result = tc.callWitness(typeRef, dc, arrayProto, conformance,
name, arg, diag::array_protocol_broken);
if (!result)
return nullptr;
expr->setSemanticExpr(result);
expr->setType(arrayTy);
return expr;
}
Expr *visitDictionaryExpr(DictionaryExpr *expr) {
Type openedType = expr->getType();
Type dictionaryTy = simplifyType(openedType);
auto &tc = cs.getTypeChecker();
ProtocolDecl *dictionaryProto
= tc.getProtocol(expr->getLoc(),
KnownProtocolKind::DictionaryLiteralConvertible);
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(dictionaryTy, dictionaryProto,
cs.DC, &conformance);
if (!conforms)
return nullptr;
// Call the witness that builds the dictionary literal.
// FIXME: callWitness() may end up re-doing some work we already did
// to convert the dictionary literal elements to the (key, value) tuple.
// It would be nicer to re-use them.
// FIXME: Cache the name.
// FIXME: This location info is bogus.
Expr *typeRef = TypeExpr::createImplicitHack(expr->getLoc(),
dictionaryTy, tc.Context);
auto name = tc.Context.Id_ConvertFromDictionaryLiteral;
auto arg = expr->getSubExpr();
Expr *result = tc.callWitness(typeRef, dc, dictionaryProto,
conformance, name, arg,
diag::dictionary_protocol_broken);
if (!result)
return nullptr;
expr->setSemanticExpr(result);
expr->setType(dictionaryTy);
return expr;
}
Expr *visitDynamicSubscriptExpr(DynamicSubscriptExpr *expr) {
return buildSubscript(expr->getBase(), expr->getIndex(),
cs.getConstraintLocator(expr));
}
Expr *visitTupleElementExpr(TupleElementExpr *expr) {
// Handle accesses that implicitly look through ImplicitlyUnwrappedOptional<T>.
auto base = expr->getBase();
auto baseTy = base->getType()->getRValueType();
if (auto objTy = cs.lookThroughImplicitlyUnwrappedOptionalType(baseTy)) {
base = coerceImplicitlyUnwrappedOptionalToValue(base, objTy,
cs.getConstraintLocator(base));
if (!base) return nullptr;
expr->setBase(base);
}
simplifyExprType(expr);
return expr;
}
Expr *visitClosureExpr(ClosureExpr *expr) {
llvm_unreachable("Handled by the walker directly");
}
Expr *visitAutoClosureExpr(AutoClosureExpr *expr) {
llvm_unreachable("Already type-checked");
}
Expr *visitModuleExpr(ModuleExpr *expr) { return expr; }
Expr *visitInOutExpr(InOutExpr *expr) {
auto lvTy = expr->getSubExpr()->getType()->castTo<LValueType>();
// The type is simply inout.
// Compute the type of the inout expression.
expr->setType(InOutType::get(lvTy->getObjectType()));
return expr;
}
Expr *visitDynamicTypeExpr(DynamicTypeExpr *expr) {
auto &tc = cs.getTypeChecker();
Expr *base = expr->getBase();
base = tc.coerceToRValue(base);
if (!base) return nullptr;
expr->setBase(base);
return simplifyExprType(expr);
}
Expr *visitOpaqueValueExpr(OpaqueValueExpr *expr) {
return expr;
}
Expr *visitDefaultValueExpr(DefaultValueExpr *expr) {
llvm_unreachable("Already type-checked");
}
Expr *visitApplyExpr(ApplyExpr *expr) {
auto result = finishApply(expr, expr->getType(),
ConstraintLocatorBuilder(
cs.getConstraintLocator(expr)));
// See if this application advanced a partial value type application.
auto foundApplication = InvalidPartialApplications.find(
expr->getFn()->getSemanticsProvidingExpr());
if (foundApplication != InvalidPartialApplications.end()) {
unsigned level = foundApplication->second.level;
assert(level > 0);
InvalidPartialApplications.erase(foundApplication);
if (level > 1)
InvalidPartialApplications.insert({
result, {
level - 1,
foundApplication->second.kind
}
});
}
return result;
}
Expr *visitRebindSelfInConstructorExpr(RebindSelfInConstructorExpr *expr) {
return expr;
}
Expr *visitIfExpr(IfExpr *expr) {
auto resultTy = simplifyType(expr->getType());
expr->setType(resultTy);
// Convert the condition to a logic value.
auto cond
= solution.convertToLogicValue(expr->getCondExpr(),
cs.getConstraintLocator(expr));
if (!cond) {
cond->setType(ErrorType::get(cs.getASTContext()));
} else {
expr->setCondExpr(cond);
}
// Coerce the then/else branches to the common type.
expr->setThenExpr(coerceToType(expr->getThenExpr(), resultTy,
ConstraintLocatorBuilder(
cs.getConstraintLocator(expr))
.withPathElement(
ConstraintLocator::IfThen)));
expr->setElseExpr(coerceToType(expr->getElseExpr(), resultTy,
ConstraintLocatorBuilder(
cs.getConstraintLocator(expr))
.withPathElement(
ConstraintLocator::IfElse)));
return expr;
}
Expr *visitImplicitConversionExpr(ImplicitConversionExpr *expr) {
llvm_unreachable("Already type-checked");
}
/// A helper function to plumb a stack of optional types.
Type plumbOptionals(Type type, SmallVectorImpl<Type> &optionals) {
while (auto valueType = type->getAnyOptionalObjectType()) {
optionals.push_back(type);
type = valueType;
}
return type;
};
Expr *visitIsaExpr(IsaExpr *expr) {
// Turn the subexpression into an rvalue.
auto &tc = cs.getTypeChecker();
auto toType = simplifyType(expr->getCastTypeLoc().getType());
auto sub = tc.coerceToRValue(expr->getSubExpr());
if (!sub)
return nullptr;
expr->setSubExpr(sub);
// Set the type we checked against.
expr->getCastTypeLoc().setType(toType, /*validated=*/true);
auto fromType = sub->getType();
auto castKind = tc.typeCheckCheckedCast(
fromType, toType, cs.DC,
expr->getLoc(),
sub->getSourceRange(),
expr->getCastTypeLoc().getSourceRange(),
[&](Type commonTy) -> bool {
return tc.convertToType(sub, commonTy, cs.DC);
});
switch (castKind) {
case CheckedCastKind::Unresolved:
// Invalid type check.
return nullptr;
case CheckedCastKind::Coercion:
// Check is trivially true.
tc.diagnose(expr->getLoc(), diag::isa_is_always_true,
expr->getSubExpr()->getType(),
expr->getCastTypeLoc().getType());
expr->setCastKind(castKind);
break;
case CheckedCastKind::ArrayDowncast:
case CheckedCastKind::ArrayDowncastBridged:
case CheckedCastKind::DictionaryDowncast:
case CheckedCastKind::DictionaryDowncastBridged:
case CheckedCastKind::Downcast:
case CheckedCastKind::SuperToArchetype:
case CheckedCastKind::ArchetypeToArchetype:
case CheckedCastKind::ArchetypeToConcrete:
case CheckedCastKind::ExistentialToArchetype:
case CheckedCastKind::ExistentialToConcrete:
case CheckedCastKind::ConcreteToArchetype:
case CheckedCastKind::ConcreteToUnrelatedExistential:
// Valid checks.
expr->setCastKind(castKind);
break;
}
// SIL-generation magically turns this into a Bool; make sure it can.
if (!cs.getASTContext().getGetBoolDecl(&cs.getTypeChecker())) {
tc.diagnose(expr->getLoc(), diag::bool_intrinsics_not_found);
// Continue anyway.
}
// Dig through the optionals in the from/to types.
SmallVector<Type, 2> fromOptionals;
auto fromValueType = plumbOptionals(fromType, fromOptionals);
SmallVector<Type, 2> toOptionals;
auto toValueType = plumbOptionals(toType, toOptionals);
// If we have an imbalance of optionals, a collection downcast, or
// are bridging through an Objective-C class, handle this as a
// checked cast followed by a getLogicValue.
if (fromOptionals.size() != toOptionals.size() ||
castKind == CheckedCastKind::ArrayDowncast ||
castKind == CheckedCastKind::DictionaryDowncast ||
tc.getDynamicBridgedThroughObjCClass(cs.DC,
fromValueType,
toValueType)) {
auto toOptType = OptionalType::get(toType);
ConditionalCheckedCastExpr *cast
= new (tc.Context) ConditionalCheckedCastExpr(
sub, expr->getLoc(), SourceLoc(),
TypeLoc::withoutLoc(toType));
cast->setType(toOptType);
if (expr->isImplicit())
cast->setImplicit();
// Type-check this conditional case.
Expr *result = visitConditionalCheckedCastExpr(cast);
if (!result)
return nullptr;
// Extract a Bool from the resulting expression.
return solution.convertOptionalToBool(result,
cs.getConstraintLocator(expr));
}
return expr;
}
/// Handle optional operands and results in an explicit cast.
Expr *handleOptionalBindings(ExplicitCastExpr *cast,
Type finalResultType,
bool conditionalCast) {
auto &tc = cs.getTypeChecker();
unsigned destExtraOptionals = conditionalCast ? 1 : 0;
// FIXME: some of this work needs to be delayed until runtime to
// properly account for archetypes dynamically being optional
// types. For example, if we're casting T to NSView?, that
// should succeed if T=NSObject? and its value is actually nil.
Expr *subExpr = cast->getSubExpr();
Type srcType = subExpr->getType();
SmallVector<Type, 4> srcOptionals;
srcType = plumbOptionals(srcType, srcOptionals);
SmallVector<Type, 4> destOptionals;
auto destValueType = plumbOptionals(finalResultType, destOptionals);
// Check whether we need to bridge the source type to the
// destination type.
Type bridgedThroughClass
= tc.getDynamicBridgedThroughObjCClass(cs.DC, srcType, destValueType);
// There's nothing special to do if the operand isn't optional
// and we don't need any bridging.
if (srcOptionals.empty() && !bridgedThroughClass) {
cast->setType(finalResultType);
return cast;
}
// If this is a conditional cast, the result type will always
// have at least one level of optional, which should become the
// type of the checked-cast expression.
if (conditionalCast) {
assert(!destOptionals.empty() &&
"result of checked cast is not an optional type");
cast->setType(destOptionals.back());
if (bridgedThroughClass)
cast->setType(OptionalType::get(bridgedThroughClass));
} else {
cast->setType(bridgedThroughClass? bridgedThroughClass : destValueType);
}
// The result type (without the final optional) is a subtype of
// the operand type, so it will never have a higher depth.
assert(destOptionals.size() - destExtraOptionals <= srcOptionals.size());
// The outermost N levels of optionals on the operand must all
// be present or the cast fails. The innermost M levels of
// optionals on the operand are reflected in the requested
// destination type, so we should map these nils into the result.
unsigned numRequiredOptionals =
srcOptionals.size() - (destOptionals.size() - destExtraOptionals);
// Determine whether we require conditional bridging.
bool requiresConditionalBridging = conditionalCast && bridgedThroughClass;
// The number of OptionalEvaluationExprs between the point of the
// inner cast and the enclosing OptionalEvaluationExpr (exclusive)
// which represents failure for the entire operation.
unsigned failureDepth = destOptionals.size() - destExtraOptionals
+ requiresConditionalBridging;
// Drill down on the operand until it's non-optional.
SourceLoc fakeQuestionLoc = subExpr->getEndLoc();
for (unsigned i : indices(srcOptionals)) {
Type valueType =
(i + 1 == srcOptionals.size() ? srcType : srcOptionals[i+1]);
// As we move into the range of mapped optionals, start
// lowering the depth.
unsigned depth = failureDepth - requiresConditionalBridging;
if (i >= numRequiredOptionals) {
depth -= (i - numRequiredOptionals) + 1;
} else if (!conditionalCast) {
// For a forced cast, force the required optionals.
subExpr = new (tc.Context) ForceValueExpr(subExpr, fakeQuestionLoc);
subExpr->setType(valueType);
subExpr->setImplicit(true);
continue;
}
subExpr = new (tc.Context) BindOptionalExpr(subExpr, fakeQuestionLoc,
depth, valueType);
subExpr->setImplicit(true);
}
cast->setSubExpr(subExpr);
// If we're casting to an optional type, we need to capture the
// final M bindings.
Expr *result = cast;
// First, handle any required bridging.
if (bridgedThroughClass) {
// If the source type is the bridged class, we don't need the
// actual cast, so grab it's subexpression.
// FIXME: This loses source information.
bool dropCast = srcType->isEqual(bridgedThroughClass);
if (dropCast)
result = cast->getSubExpr();
if (requiresConditionalBridging) {
// When conditionally bridging, we need to carry through the
// optional.
if (!dropCast) {
result = new (tc.Context) BindOptionalExpr(result,
cast->getEndLoc(),
failureDepth,
bridgedThroughClass);
result->setImplicit(true);
}
result = bridgeFromObjectiveCConditional(result, destValueType);
if (!result)
return nullptr;
// Update type sugar.
result->setType(OptionalType::get(destValueType));
if (!dropCast) {
result = new (tc.Context) OptionalEvaluationExpr(
result,
OptionalType::get(destValueType));
}
} else {
result = bridgeFromObjectiveC(result, destValueType);
if (!result)
return nullptr;
// Update type sugar.
result->setType(destValueType);
}
}
if (destOptionals.size() > destExtraOptionals) {
if (conditionalCast) {
// If the innermost cast fails, the entire expression fails. To
// get this behavior, we have to bind and then re-inject the result.
// (SILGen should know how to peephole this.)
result = new (tc.Context) BindOptionalExpr(result, cast->getEndLoc(),
failureDepth-requiresConditionalBridging,
destValueType);
result->setImplicit(true);
}
for (unsigned i = destOptionals.size(); i != 0; --i) {
Type destType = destOptionals[i-1];
result = new (tc.Context) InjectIntoOptionalExpr(result, destType);
result = new (tc.Context) OptionalEvaluationExpr(result, destType);
}
// Otherwise, we just need to capture the failure-depth binding.
} else if (conditionalCast) {
result = new (tc.Context) OptionalEvaluationExpr(result,
finalResultType);
}
return result;
}
Expr *visitUnresolvedCheckedCastExpr(UnresolvedCheckedCastExpr *expr) {
// Simplify the type we're casting to.
auto toType = simplifyType(expr->getCastTypeLoc().getType());
expr->getCastTypeLoc().setType(toType, /*validated=*/true);
// Determine whether we performed a coercion or a downcast.
auto locator
= cs.getConstraintLocator(expr, ConstraintLocator::CheckedCastOperand);
unsigned choice = solution.getDisjunctionChoice(locator);
assert(choice <= 1 && "checked cast choices not synced with disjunction");
auto &tc = cs.getTypeChecker();
auto sub = tc.coerceToRValue(expr->getSubExpr());
// Choice 0 is coercion.
if (choice == 0) {
// The subexpression is always an rvalue.
if (!sub)
return nullptr;
// Convert the subexpression.
bool failed = tc.convertToType(sub, toType, cs.DC);
(void)failed;
assert(!failed && "Not convertible?");
// Transmute the checked cast into a coercion expression.
Expr *result = new (tc.Context) CoerceExpr(sub, expr->getLoc(),
expr->getCastTypeLoc());
// The result type is the type we're converting to.
result->setType(toType);
return result;
}
// Choice 1 is downcast.
assert(choice == 1);
auto fromType = sub->getType();
auto castKind = tc.typeCheckCheckedCast(
fromType, toType, cs.DC,
expr->getLoc(),
sub->getSourceRange(),
expr->getCastTypeLoc().getSourceRange(),
[&](Type commonTy) -> bool {
return tc.convertToType(sub, commonTy,
cs.DC);
});
switch (castKind) {
/// Invalid cast.
case CheckedCastKind::Unresolved:
return nullptr;
case CheckedCastKind::Coercion:
llvm_unreachable("Coercions handled above");
// Valid casts.
case CheckedCastKind::ArrayDowncast:
case CheckedCastKind::ArrayDowncastBridged:
case CheckedCastKind::DictionaryDowncast:
case CheckedCastKind::DictionaryDowncastBridged:
case CheckedCastKind::Downcast:
case CheckedCastKind::SuperToArchetype:
case CheckedCastKind::ArchetypeToArchetype:
case CheckedCastKind::ArchetypeToConcrete:
case CheckedCastKind::ExistentialToArchetype:
case CheckedCastKind::ExistentialToConcrete:
case CheckedCastKind::ConcreteToArchetype:
case CheckedCastKind::ConcreteToUnrelatedExistential:
break;
}
auto *cast = new (tc.Context) ForcedCheckedCastExpr(
sub,
expr->getLoc(),
expr->getCastTypeLoc());
cast->setType(toType);
cast->setCastKind(castKind);
if (expr->isImplicit())
cast->setImplicit();
return handleOptionalBindings(cast, simplifyType(expr->getType()),
/*conditionalCast=*/false);
}
Expr *visitForcedCheckedCastExpr(ForcedCheckedCastExpr *expr) {
llvm_unreachable("Already type-checked");
}
Expr *visitConditionalCheckedCastExpr(ConditionalCheckedCastExpr *expr) {
// Simplify the type we're casting to.
auto toType = simplifyType(expr->getCastTypeLoc().getType());
expr->getCastTypeLoc().setType(toType, /*validated=*/true);
// The subexpression is always an rvalue.
auto &tc = cs.getTypeChecker();
auto sub = tc.coerceToRValue(expr->getSubExpr());
if (!sub)
return nullptr;
expr->setSubExpr(sub);
auto fromType = sub->getType();
auto castKind = tc.typeCheckCheckedCast(
fromType, toType, cs.DC,
expr->getLoc(),
sub->getSourceRange(),
expr->getCastTypeLoc().getSourceRange(),
[&](Type commonTy) -> bool {
return tc.convertToType(sub, commonTy,
cs.DC);
});
switch (castKind) {
/// Invalid cast.
case CheckedCastKind::Unresolved:
return nullptr;
case CheckedCastKind::Coercion: {
tc.diagnose(expr->getLoc(), diag::conditional_downcast_coercion,
sub->getType(), toType);
// Convert the subexpression.
bool failed = tc.convertToType(sub, toType, cs.DC);
(void)failed;
assert(!failed && "Not convertible?");
// Transmute the checked cast into a coercion expression.
Expr *result = new (tc.Context) CoerceExpr(sub, expr->getLoc(),
expr->getCastTypeLoc());
// The result type is the type we're converting to.
result->setType(toType);
// Wrap the result in an optional.
return new (tc.Context) InjectIntoOptionalExpr(
result,
OptionalType::get(toType));
}
// Valid casts.
case CheckedCastKind::ArrayDowncast:
case CheckedCastKind::ArrayDowncastBridged:
case CheckedCastKind::DictionaryDowncast:
case CheckedCastKind::DictionaryDowncastBridged:
case CheckedCastKind::Downcast:
case CheckedCastKind::SuperToArchetype:
case CheckedCastKind::ArchetypeToArchetype:
case CheckedCastKind::ArchetypeToConcrete:
case CheckedCastKind::ExistentialToArchetype:
case CheckedCastKind::ExistentialToConcrete:
case CheckedCastKind::ConcreteToArchetype:
case CheckedCastKind::ConcreteToUnrelatedExistential:
expr->setCastKind(castKind);
break;
}
return handleOptionalBindings(expr, simplifyType(expr->getType()),
/*conditionalCast=*/true);
}
Expr *visitCoerceExpr(CoerceExpr *expr) {
return expr;
}
Expr *visitAssignExpr(AssignExpr *expr) {
llvm_unreachable("Handled by ExprWalker");
}
Expr *visitAssignExpr(AssignExpr *expr, ConstraintLocator *srcLocator) {
// Compute the type to which the source must be converted to allow
// assignment to the destination.
//
// FIXME: This is also computed when the constraint system is set up.
auto destTy = cs.computeAssignDestType(expr->getDest(), expr->getLoc());
if (!destTy)
return nullptr;
// Convert the source to the simplified destination type.
Expr *src = solution.coerceToType(expr->getSrc(),
destTy,
srcLocator);
if (!src)
return nullptr;
expr->setSrc(src);
return expr;
}
Expr *visitDiscardAssignmentExpr(DiscardAssignmentExpr *expr) {
return simplifyExprType(expr);
}
Expr *visitUnresolvedPatternExpr(UnresolvedPatternExpr *expr) {
llvm_unreachable("should have been eliminated during name binding");
}
Expr *visitBindOptionalExpr(BindOptionalExpr *expr) {
Type valueType = simplifyType(expr->getType());
Type optType =
cs.getTypeChecker().getOptionalType(expr->getQuestionLoc(), valueType);
if (!optType) return nullptr;
Expr *subExpr = coerceToType(expr->getSubExpr(), optType,
cs.getConstraintLocator(expr));
if (!subExpr) return nullptr;
// Complain if the sub-expression was converted to T? via the
// inject-into-optional implicit conversion.
//
// It should be the case that that's always the last conversion applied.
if (auto injection = dyn_cast<InjectIntoOptionalExpr>(subExpr)) {
// If the sub-expression was a forced downcast, suggest
// turning it into a conditional downcast.
auto &tc = cs.getTypeChecker();
if (auto forced = findForcedDowncast(tc.Context,
injection->getSubExpr())) {
tc.diagnose(expr->getLoc(), diag::binding_explicit_downcast,
injection->getSubExpr()->getType()->getRValueType())
.highlight(forced->getLoc())
.fixItInsert(Lexer::getLocForEndOfToken(tc.Context.SourceMgr,
forced->getLoc()),
"?");
} else {
tc.diagnose(subExpr->getLoc(), diag::binding_injected_optional,
expr->getSubExpr()->getType()->getRValueType())
.highlight(subExpr->getSourceRange())
.fixItRemove(expr->getQuestionLoc());
}
// Don't diagnose this injection again.
DiagnosedOptionalInjections.insert(injection);
}
expr->setSubExpr(subExpr);
expr->setType(valueType);
return expr;
}
Expr *visitOptionalEvaluationExpr(OptionalEvaluationExpr *expr) {
Type optType = simplifyType(expr->getType());
Expr *subExpr = coerceToType(expr->getSubExpr(), optType,
cs.getConstraintLocator(expr));
if (!subExpr) return nullptr;
expr->setSubExpr(subExpr);
expr->setType(optType);
return expr;
}
Expr *visitForceValueExpr(ForceValueExpr *expr) {
Type valueType = simplifyType(expr->getType());
expr->setType(valueType);
return expr;
}
Expr *visitOpenExistentialExpr(OpenExistentialExpr *expr) {
llvm_unreachable("Already type-checked");
}
void finalize() {
// Check that all value type methods were fully applied.
auto &tc = cs.getTypeChecker();
for (auto &unapplied : InvalidPartialApplications) {
unsigned kind = unapplied.second.kind;
tc.diagnose(unapplied.first->getLoc(),
diag::partial_application_of_method_invalid,
kind);
}
// We should have complained above if there were any
// existentials that haven't been closed yet.
assert((OpenedExistentials.empty() ||
!InvalidPartialApplications.empty()) &&
"Opened existentials have not been closed");
// Look at all of the suspicious optional injections
for (auto injection : SuspiciousOptionalInjections) {
// If we already diagnosed this injection, we're done.
if (DiagnosedOptionalInjections.count(injection)) {
continue;
}
auto *cast = findForcedDowncast(tc.Context, injection->getSubExpr());
if (!cast)
continue;
if (isa<ParenExpr>(injection->getSubExpr()))
continue;
tc.diagnose(injection->getLoc(), diag::inject_forced_downcast,
injection->getSubExpr()->getType()->getRValueType());
auto questionLoc = Lexer::getLocForEndOfToken(tc.Context.SourceMgr,
cast->getLoc());
tc.diagnose(questionLoc, diag::forced_to_conditional_downcast,
injection->getType()->getAnyOptionalObjectType())
.fixItInsert(questionLoc, "?");
auto pastEndLoc = Lexer::getLocForEndOfToken(tc.Context.SourceMgr,
cast->getEndLoc());
tc.diagnose(cast->getStartLoc(), diag::silence_inject_forced_downcast)
.fixItInsert(cast->getStartLoc(), "(")
.fixItInsert(pastEndLoc, ")");
}
}
/// Diagnose an optional injection that is probably not what the
/// user wanted, because it comes from a forced downcast.
void diagnoseOptionalInjection(InjectIntoOptionalExpr *injection) {
// Don't diagnose when we're injecting into
auto toOptionalType = injection->getType();
if (toOptionalType->getImplicitlyUnwrappedOptionalObjectType())
return;
// Check whether we have a forced downcast.
auto &tc = cs.getTypeChecker();
auto *cast = findForcedDowncast(tc.Context, injection->getSubExpr());
if (!cast)
return;
SuspiciousOptionalInjections.push_back(injection);
}
};
}
/// \brief Given a constraint locator, find the owner of default arguments for
/// that tuple, i.e., a FuncDecl.
static ConcreteDeclRef
findDefaultArgsOwner(ConstraintSystem &cs, const Solution &solution,
ConstraintLocator *locator) {
if (locator->getPath().empty() || !locator->getAnchor())
return nullptr;
// If the locator points to a function application, find the function itself.
if (locator->getPath().back().getKind() == ConstraintLocator::ApplyArgument) {
assert(locator->getPath().back().getNewSummaryFlags() == 0 &&
"ApplyArgument adds no flags");
SmallVector<LocatorPathElt, 4> newPath;
newPath.append(locator->getPath().begin(), locator->getPath().end()-1);
unsigned newFlags = locator->getSummaryFlags();
// If we have an interpolation argument, dig out the constructor if we
// can.
// FIXME: This representation is actually quite awful
if (newPath.size() == 1 &&
newPath[0].getKind() == ConstraintLocator::InterpolationArgument) {
newPath.push_back(ConstraintLocator::ConstructorMember);
locator = cs.getConstraintLocator(locator->getAnchor(), newPath, newFlags);
auto known = solution.overloadChoices.find(locator);
if (known != solution.overloadChoices.end()) {
auto &choice = known->second.choice;
if (choice.getKind() == OverloadChoiceKind::Decl)
return cast<AbstractFunctionDecl>(choice.getDecl());
}
return nullptr;
} else {
newPath.push_back(ConstraintLocator::ApplyFunction);
}
assert(newPath.back().getNewSummaryFlags() == 0 &&
"added element that changes the flags?");
locator = cs.getConstraintLocator(locator->getAnchor(), newPath, newFlags);
}
// Simplify the locator.
SourceRange range1, range2;
locator = simplifyLocator(cs, locator, range1, range2);
// If we didn't map down to a specific expression, we can't handle a default
// argument.
if (!locator->getAnchor() || !locator->getPath().empty())
return nullptr;
if (auto resolved
= resolveLocatorToDecl(cs, locator,
[&](ConstraintLocator *locator) -> Optional<SelectedOverload> {
auto known = solution.overloadChoices.find(locator);
if (known == solution.overloadChoices.end()) {
return Nothing;
}
return known->second;
},
[&](ValueDecl *decl,
Type openedType) -> ConcreteDeclRef {
if (decl->getPotentialGenericDeclContext()->isGenericContext()) {
SmallVector<Substitution, 4> subs;
solution.computeSubstitutions(decl->getType(),
decl->getPotentialGenericDeclContext(),
openedType, subs);
return ConcreteDeclRef(cs.getASTContext(), decl, subs);
}
return decl;
})) {
return resolved.getDecl();
}
return nullptr;
}
/// Produce the caller-side default argument for this default argument, or
/// null if the default argument will be provided by the callee.
static Expr *getCallerDefaultArg(TypeChecker &tc, DeclContext *dc,
SourceLoc loc, ConcreteDeclRef &owner,
unsigned index) {
auto ownerFn = cast<AbstractFunctionDecl>(owner.getDecl());
auto defArg = ownerFn->getDefaultArg(index);
MagicIdentifierLiteralExpr::Kind magicKind;
switch (defArg.first) {
case DefaultArgumentKind::None:
llvm_unreachable("No default argument here?");
case DefaultArgumentKind::Normal:
return nullptr;
case DefaultArgumentKind::Inherited:
// Update the owner to reflect inheritance here.
owner = ownerFn->getOverriddenDecl();
return getCallerDefaultArg(tc, dc, loc, owner, index);
case DefaultArgumentKind::Column:
magicKind = MagicIdentifierLiteralExpr::Column;
break;
case DefaultArgumentKind::File:
magicKind = MagicIdentifierLiteralExpr::File;
break;
case DefaultArgumentKind::Line:
magicKind = MagicIdentifierLiteralExpr::Line;
break;
case DefaultArgumentKind::Function:
magicKind = MagicIdentifierLiteralExpr::Function;
break;
}
// Create the default argument, which is a converted magic identifier
// literal expression.
Expr *init = new (tc.Context) MagicIdentifierLiteralExpr(magicKind, loc,
/*Implicit=*/true);
bool invalid = tc.typeCheckExpression(init, dc, defArg.second, Type(),
/*discardedExpr=*/false);
assert(!invalid && "conversion cannot fail");
(void)invalid;
return init;
}
/// Rebuild the ParenTypes for the given expression, whose underlying expression
/// should be set to the given type.
static Type rebuildParenType(ASTContext &ctx, Expr *expr, Type type) {
if (auto paren = dyn_cast<ParenExpr>(expr)) {
type = rebuildParenType(ctx, paren->getSubExpr(), type);
paren->setType(ParenType::get(ctx, type));
return paren->getType();
}
if (auto ident = dyn_cast<IdentityExpr>(expr)) {
type = rebuildParenType(ctx, ident->getSubExpr(), type);
ident->setType(type);
return ident->getType();
}
return type;
}
Expr *ExprRewriter::coerceTupleToTuple(Expr *expr, TupleType *fromTuple,
TupleType *toTuple,
ConstraintLocatorBuilder locator,
SmallVectorImpl<int> &sources,
SmallVectorImpl<unsigned> &variadicArgs){
auto &tc = cs.getTypeChecker();
// Capture the tuple expression, if there is one.
Expr *innerExpr = expr;
while (auto paren = dyn_cast<IdentityExpr>(innerExpr))
innerExpr = paren->getSubExpr();
TupleExpr *fromTupleExpr = dyn_cast<TupleExpr>(innerExpr);
/// Check each of the tuple elements in the destination.
bool hasVarArg = false;
bool anythingShuffled = false;
bool hasInits = false;
SmallVector<TupleTypeElt, 4> toSugarFields;
SmallVector<TupleTypeElt, 4> fromTupleExprFields(
fromTuple->getFields().size());
SmallVector<Expr *, 2> callerDefaultArgs;
ConcreteDeclRef defaultArgsOwner;
for (unsigned i = 0, n = toTuple->getFields().size(); i != n; ++i) {
const auto &toElt = toTuple->getFields()[i];
auto toEltType = toElt.getType();
// If we're default-initializing this member, there's nothing to do.
if (sources[i] == TupleShuffleExpr::DefaultInitialize) {
// Dig out the owner of the default arguments.
if (!defaultArgsOwner) {
defaultArgsOwner
= findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator));
assert(defaultArgsOwner && "Missing default arguments owner?");
} else {
assert(findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator))
== defaultArgsOwner);
}
anythingShuffled = true;
hasInits = true;
toSugarFields.push_back(toElt);
// Create a caller-side default argument, if we need one.
if (auto defArg = getCallerDefaultArg(tc, dc, expr->getLoc(),
defaultArgsOwner, i)) {
callerDefaultArgs.push_back(defArg);
sources[i] = TupleShuffleExpr::CallerDefaultInitialize;
}
continue;
}
// If this is the variadic argument, note it.
if (sources[i] == TupleShuffleExpr::FirstVariadic) {
assert(i == n-1 && "Vararg not at the end?");
toSugarFields.push_back(toElt);
hasVarArg = true;
anythingShuffled = true;
continue;
}
// If the source and destination index are different, we'll be shuffling.
if ((unsigned)sources[i] != i) {
anythingShuffled = true;
}
// We're matching one element to another. If the types already
// match, there's nothing to do.
const auto &fromElt = fromTuple->getFields()[sources[i]];
auto fromEltType = fromElt.getType();
if (fromEltType->isEqual(toEltType)) {
// Get the sugared type directly from the tuple expression, if there
// is one.
if (fromTupleExpr)
fromEltType = fromTupleExpr->getElement(sources[i])->getType();
toSugarFields.push_back(TupleTypeElt(fromEltType,
toElt.getName(),
toElt.getDefaultArgKind(),
toElt.isVararg()));
fromTupleExprFields[sources[i]] = fromElt;
hasInits |= toElt.hasInit();
continue;
}
// We need to convert the source element to the destination type.
if (!fromTupleExpr) {
// FIXME: Lame! We can't express this in the AST.
tc.diagnose(expr->getLoc(),
diag::tuple_conversion_not_expressible,
fromTuple, toTuple);
return nullptr;
}
// Actually convert the source element.
auto convertedElt
= coerceToType(fromTupleExpr->getElement(sources[i]), toEltType,
locator.withPathElement(
LocatorPathElt::getTupleElement(sources[i])));
if (!convertedElt)
return nullptr;
fromTupleExpr->setElement(sources[i], convertedElt);
// Record the sugared field name.
toSugarFields.push_back(TupleTypeElt(convertedElt->getType(),
toElt.getName(),
toElt.getDefaultArgKind(),
toElt.isVararg()));
fromTupleExprFields[sources[i]] = TupleTypeElt(convertedElt->getType(),
fromElt.getName(),
fromElt.getDefaultArgKind(),
fromElt.isVararg());
hasInits |= toElt.hasInit();
}
// Convert all of the variadic arguments to the destination type.
Expr *injectionFn = nullptr;
if (hasVarArg) {
Type toEltType = toTuple->getFields().back().getVarargBaseTy();
for (int fromFieldIdx : variadicArgs) {
const auto &fromElt = fromTuple->getFields()[fromFieldIdx];
Type fromEltType = fromElt.getType();
// If the source and destination types match, there's nothing to do.
if (toEltType->isEqual(fromEltType)) {
sources.push_back(fromFieldIdx);
fromTupleExprFields[fromFieldIdx] = fromElt;
continue;
}
// We need to convert the source element to the destination type.
if (!fromTupleExpr) {
// FIXME: Lame! We can't express this in the AST.
tc.diagnose(expr->getLoc(),
diag::tuple_conversion_not_expressible,
fromTuple, toTuple);
return nullptr;
}
// Actually convert the source element.
auto convertedElt = coerceToType(
fromTupleExpr->getElement(fromFieldIdx),
toEltType,
locator.withPathElement(
LocatorPathElt::getTupleElement(fromFieldIdx)));
if (!convertedElt)
return nullptr;
fromTupleExpr->setElement(fromFieldIdx, convertedElt);
sources.push_back(fromFieldIdx);
fromTupleExprFields[fromFieldIdx] = TupleTypeElt(
convertedElt->getType(),
fromElt.getName(),
fromElt.getDefaultArgKind(),
fromElt.isVararg());
}
// Find the appropriate injection function.
ArraySliceType *sliceType
= cast<ArraySliceType>(
toTuple->getFields().back().getType().getPointer());
Type boundType = BuiltinIntegerType::getWordType(tc.Context);
injectionFn = tc.buildArrayInjectionFnRef(dc,
sliceType, boundType,
expr->getStartLoc());
if (!injectionFn)
return nullptr;
}
// Compute the updated 'from' tuple type, since we may have
// performed some conversions in place.
Type fromTupleType = TupleType::get(fromTupleExprFields, tc.Context);
if (fromTupleExpr) {
fromTupleExpr->setType(fromTupleType);
// Update the types of parentheses around the tuple expression.
rebuildParenType(cs.getASTContext(), expr, fromTupleType);
}
// Compute the re-sugared tuple type.
Type toSugarType = hasInits? toTuple
: TupleType::get(toSugarFields, tc.Context);
// If we don't have to shuffle anything, we're done.
if (!anythingShuffled && fromTupleExpr) {
fromTupleExpr->setType(toSugarType);
// Update the types of parentheses around the tuple expression.
rebuildParenType(cs.getASTContext(), expr, toSugarType);
return expr;
}
// Create the tuple shuffle.
ArrayRef<int> mapping = tc.Context.AllocateCopy(sources);
auto callerDefaultArgsCopy = tc.Context.AllocateCopy(callerDefaultArgs);
auto shuffle = new (tc.Context) TupleShuffleExpr(expr, mapping,
defaultArgsOwner,
callerDefaultArgsCopy,
toSugarType);
shuffle->setVarargsInjectionFunction(injectionFn);
return shuffle;
}
Expr *ExprRewriter::coerceScalarToTuple(Expr *expr, TupleType *toTuple,
int toScalarIdx,
ConstraintLocatorBuilder locator) {
auto &tc = solution.getConstraintSystem().getTypeChecker();
// If the destination type is variadic, compute the injection function to use.
Expr *injectionFn = nullptr;
const auto &lastField = toTuple->getFields().back();
if (lastField.isVararg()) {
// Find the appropriate injection function.
ArraySliceType *sliceType
= cast<ArraySliceType>(lastField.getType().getPointer());
Type boundType = BuiltinIntegerType::getWordType(tc.Context);
injectionFn = tc.buildArrayInjectionFnRef(dc,
sliceType, boundType,
expr->getStartLoc());
if (!injectionFn)
return nullptr;
}
// If we're initializing the varargs list, use its base type.
const auto &field = toTuple->getFields()[toScalarIdx];
Type toScalarType;
if (field.isVararg())
toScalarType = field.getVarargBaseTy();
else
toScalarType = field.getType();
// Coerce the expression to the type to the scalar type.
expr = coerceToType(expr, toScalarType,
locator.withPathElement(
ConstraintLocator::ScalarToTuple));
if (!expr)
return nullptr;
// Preserve the sugar of the scalar field.
// FIXME: This doesn't work if the type has default values because they fail
// to canonicalize.
SmallVector<TupleTypeElt, 4> sugarFields;
bool hasInit = false;
int i = 0;
for (auto &field : toTuple->getFields()) {
if (field.hasInit()) {
hasInit = true;
break;
}
if (i == toScalarIdx) {
if (field.isVararg()) {
assert(expr->getType()->isEqual(field.getVarargBaseTy()) &&
"scalar field is not equivalent to dest vararg field?!");
sugarFields.push_back(TupleTypeElt(field.getType(),
field.getName(),
field.getDefaultArgKind(),
true));
}
else {
assert(expr->getType()->isEqual(field.getType()) &&
"scalar field is not equivalent to dest tuple field?!");
sugarFields.push_back(TupleTypeElt(expr->getType(),
field.getName()));
}
// Record the
} else {
sugarFields.push_back(field);
}
++i;
}
// Compute the elements of the resulting tuple.
SmallVector<ScalarToTupleExpr::Element, 4> elements;
ConcreteDeclRef defaultArgsOwner = nullptr;
i = 0;
for (auto &field : toTuple->getFields()) {
// Use a null entry to indicate that this is the scalar field.
if (i == toScalarIdx) {
elements.push_back(ScalarToTupleExpr::Element());
++i;
continue;
}
if (field.isVararg()) {
++i;
continue;
}
assert(field.hasInit() && "Expected a default argument");
// Dig out the owner of the default arguments.
if (!defaultArgsOwner) {
defaultArgsOwner
= findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator));
assert(defaultArgsOwner && "Missing default arguments owner?");
} else {
assert(findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator))
== defaultArgsOwner);
}
// Create a caller-side default argument, if we need one.
if (auto defArg = getCallerDefaultArg(tc, dc, expr->getLoc(),
defaultArgsOwner, i)) {
// Record the caller-side default argument expression.
// FIXME: Do we need to record what this was synthesized from?
elements.push_back(defArg);
} else {
// Record the owner of the default argument.
elements.push_back(defaultArgsOwner);
}
++i;
}
Type destSugarTy = hasInit? toTuple
: TupleType::get(sugarFields, tc.Context);
return new (tc.Context) ScalarToTupleExpr(expr, destSugarTy,
tc.Context.AllocateCopy(elements),
injectionFn);
}
/// Collect the conformances for all the protocols of an existential type.
static ArrayRef<ProtocolConformance*>
collectExistentialConformances(TypeChecker &tc, Type fromType, Type toType,
DeclContext *DC) {
SmallVector<ProtocolDecl *, 4> protocols;
toType->getAnyExistentialTypeProtocols(protocols);
SmallVector<ProtocolConformance *, 4> conformances;
for (auto proto : protocols) {
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(fromType, proto, DC, &conformance);
assert(conforms && "Type does not conform to protocol?");
(void)conforms;
conformances.push_back(conformance);
}
return tc.Context.AllocateCopy(conformances);
}
Expr *ExprRewriter::coerceExistential(Expr *expr, Type toType,
ConstraintLocatorBuilder locator) {
auto &tc = solution.getConstraintSystem().getTypeChecker();
Type fromType = expr->getType();
if (auto bridgedType = tc.getDynamicBridgedThroughObjCClass(cs.DC, toType,
fromType)) {
// Protect against "no-op" conversions. If the bridged type points back
// to itself, the constraint solver won't have a conversion handy to
// coerce to a user conversion, so we should avoid creating a new
// expression node.
if (!bridgedType->isEqual(fromType) && !bridgedType->isEqual(toType)) {
expr = coerceViaUserConversion(expr, bridgedType, locator);
fromType = bridgedType;
}
}
// Handle existential coercions that implicitly look through ImplicitlyUnwrappedOptional<T>.
if (auto ty = cs.lookThroughImplicitlyUnwrappedOptionalType(fromType)) {
expr = coerceImplicitlyUnwrappedOptionalToValue(expr, ty, locator);
if (!expr) return nullptr;
fromType = expr->getType();
// FIXME: Hack. We shouldn't try to coerce existential when there is no
// existential upcast to perform.
if (fromType->isEqual(toType))
return expr;
}
auto conformances =
collectExistentialConformances(tc, fromType, toType, cs.DC);
return new (tc.Context) ErasureExpr(expr, toType, conformances);
}
Expr *ExprRewriter::coerceExistentialMetatype(Expr *expr, Type toType,
ConstraintLocatorBuilder locator) {
auto &tc = solution.getConstraintSystem().getTypeChecker();
Type fromType = expr->getType();
Type fromInstanceType = fromType->castTo<AnyMetatypeType>()->getInstanceType();
Type toInstanceType =
toType->castTo<ExistentialMetatypeType>()->getInstanceType();
auto conformances =
collectExistentialConformances(tc, fromInstanceType, toInstanceType, cs.DC);
return new (tc.Context) MetatypeErasureExpr(expr, toType, conformances);
}
Expr *ExprRewriter::coerceViaUserConversion(Expr *expr, Type toType,
ConstraintLocatorBuilder locator) {
auto &tc = solution.getConstraintSystem().getTypeChecker();
// Determine the locator that corresponds to the conversion member.
auto storedLocator
= cs.getConstraintLocator(
locator.withPathElement(ConstraintLocator::ConversionMember));
auto knownOverload = solution.overloadChoices.find(storedLocator);
if (knownOverload != solution.overloadChoices.end()) {
auto selected = knownOverload->second;
// FIXME: Location information is suspect throughout.
// Form a reference to the conversion member.
auto memberRef = buildMemberRef(expr,
selected.openedFullType,
expr->getStartLoc(),
selected.choice.getDecl(),
expr->getEndLoc(),
selected.openedType,
locator,
/*Implicit=*/true, /*direct ivar*/false);
// Form an empty tuple.
Expr *args = TupleExpr::createEmpty(tc.Context,
expr->getStartLoc(),
expr->getEndLoc(),
/*Implicit=*/true);
// Call the conversion function with an empty tuple.
ApplyExpr *apply = new (tc.Context) CallExpr(memberRef, args,
/*Implicit=*/true);
auto openedType = selected.openedType->castTo<FunctionType>()->getResult();
expr = finishApply(apply, openedType,
ConstraintLocatorBuilder(
cs.getConstraintLocator(apply)));
if (!expr)
return nullptr;
return coerceToType(expr, toType, locator);
}
// If there was no conversion member, look for a constructor member.
// This is only used for handling interpolated string literals, where
// we allow construction or conversion.
storedLocator
= cs.getConstraintLocator(
locator.withPathElement(ConstraintLocator::ConstructorMember));
knownOverload = solution.overloadChoices.find(storedLocator);
// Could not find a user conversion.
if(knownOverload == solution.overloadChoices.end()) {
tc.diagnose(expr->getLoc(), diag::could_not_find_user_conversion,
expr->getType(), toType);
return nullptr;
}
auto selected = knownOverload->second;
// FIXME: Location information is suspect throughout.
// Form a reference to the constructor.
// Form a reference to the constructor or enum declaration.
// FIXME: Bogus location info.
Expr *typeBase = TypeExpr::createImplicitHack(expr->getStartLoc(), toType,
tc.Context);
Expr *declRef = buildMemberRef(typeBase,
selected.openedFullType,
expr->getStartLoc(),
selected.choice.getDecl(),
expr->getStartLoc(),
selected.openedType,
storedLocator,
/*Implicit=*/true, /*direct ivar*/false);
// FIXME: Lack of openedType here is an issue.
ApplyExpr *apply = new (tc.Context) CallExpr(declRef, expr,
/*Implicit=*/true);
expr = finishApply(apply, toType, locator);
if (!expr)
return nullptr;
return coerceToType(expr, toType, locator);
}
static uint getOptionalBindDepth(const BoundGenericType *bgt) {
if (bgt->getDecl()->classifyAsOptionalType()) {
auto tyarg = bgt->getGenericArgs()[0];
uint innerDepth = 0;
if (auto wrappedBGT = dyn_cast<BoundGenericType>(tyarg->
getCanonicalType())) {
innerDepth = getOptionalBindDepth(wrappedBGT);
}
return 1 + innerDepth;
}
return 0;
}
static Type getOptionalBaseType(const Type &type) {
if (auto bgt = dyn_cast<BoundGenericType>(type->
getCanonicalType())) {
if (bgt->getDecl()->classifyAsOptionalType()) {
return getOptionalBaseType(bgt->getGenericArgs()[0]);
}
}
return type;
}
Expr *ExprRewriter::coerceOptionalToOptional(Expr *expr, Type toType,
ConstraintLocatorBuilder locator) {
auto &tc = cs.getTypeChecker();
Type fromType = expr->getType();
auto fromGenericType = fromType->castTo<BoundGenericType>();
auto toGenericType = toType->castTo<BoundGenericType>();
assert(fromGenericType->getDecl()->classifyAsOptionalType());
assert(toGenericType->getDecl()->classifyAsOptionalType());
tc.requireOptionalIntrinsics(expr->getLoc());
Type fromValueType = fromGenericType->getGenericArgs()[0];
Type toValueType = toGenericType->getGenericArgs()[0];
// If the option kinds are the same, and the wrapped types are the same,
// but the arities are different, we can peephole the optional-to-optional
// conversion into a series of nested injections.
auto toDepth = getOptionalBindDepth(toGenericType);
auto fromDepth = getOptionalBindDepth(fromGenericType);
if (toDepth > fromDepth) {
auto toBaseType = getOptionalBaseType(toGenericType);
auto fromBaseType = getOptionalBaseType(fromGenericType);
if ((toGenericType->getDecl() == fromGenericType->getDecl()) &&
toBaseType->isEqual(fromBaseType)) {
auto diff = toDepth - fromDepth;
auto isIUO = fromGenericType->getDecl()->
classifyAsOptionalType() == OTK_ImplicitlyUnwrappedOptional;
while (diff) {
const Type &t = expr->getType();
const Type &wrapped = isIUO ?
Type(ImplicitlyUnwrappedOptionalType::get(t)) :
Type(OptionalType::get(t));
expr = new (tc.Context) InjectIntoOptionalExpr(expr, wrapped);
diagnoseOptionalInjection(cast<InjectIntoOptionalExpr>(expr));
diff--;
}
return expr;
}
}
expr = new (tc.Context) BindOptionalExpr(expr, expr->getSourceRange().End,
/*depth*/ 0, fromValueType);
expr->setImplicit(true);
expr = coerceToType(expr, toValueType, locator);
if (!expr) return nullptr;
expr = new (tc.Context) InjectIntoOptionalExpr(expr, toType);
expr = new (tc.Context) OptionalEvaluationExpr(expr, toType);
expr->setImplicit(true);
return expr;
}
Expr *ExprRewriter::coerceImplicitlyUnwrappedOptionalToValue(Expr *expr, Type objTy,
ConstraintLocatorBuilder locator) {
auto optTy = expr->getType();
// Coerce to an r-value.
if (optTy->is<LValueType>())
objTy = LValueType::get(objTy);
expr = new (cs.getTypeChecker().Context) ForceValueExpr(expr, expr->getEndLoc());
expr->setType(objTy);
expr->setImplicit();
return expr;
}
Expr *ExprRewriter::coerceCallArguments(Expr *arg, Type paramType,
ConstraintLocatorBuilder locator) {
// If the types match exactly, there's nothing to do.
// FIXME: This is propping up string literals, but it feels wrong.
if (arg->getType()->isEqual(paramType))
return arg;
// Determine the parameter bindings.
MatchCallArgumentListener listener;
TupleTypeElt paramScalar;
ArrayRef<TupleTypeElt> paramTuple = decomposeArgParamType(paramType,
paramScalar);
TupleTypeElt argScalar;
ArrayRef<TupleTypeElt> argTupleElts = decomposeArgParamType(arg->getType(),
argScalar);
SmallVector<ParamBinding, 4> parameterBindings;
bool failed = constraints::matchCallArguments(argTupleElts, paramTuple,
/*allowFixes=*/false, listener,
parameterBindings);
assert(!failed && "Call arguments did not match up?");
(void)failed;
// We should either have parentheses or a tuple.
TupleExpr *argTuple = dyn_cast<TupleExpr>(arg);
ParenExpr *argParen = dyn_cast<ParenExpr>(arg);
// FIXME: Eventually, we want to enforce that we have either argTuple or
// argParen here.
// Local function to extract the ith argument expression, which papers
// over some of the weirdness with tuples vs. parentheses.
auto getArg = [&](unsigned i) -> Expr * {
if (argTuple)
return argTuple->getElements()[i];
assert(i == 0 && "Scalar only has a single argument");
if (argParen)
return argParen->getSubExpr();
return arg;
};
// Local function to extract the ith argument label, which papers over some
// of the weirdndess with tuples vs. parentheses.
auto getArgLabel = [&](unsigned i) -> Identifier {
if (argTuple)
return argTuple->getElementName(i);
assert(i == 0 && "Scalar only has a single argument");
return Identifier();
};
// Local function to produce a locator to refer to the ith element of the
// argument tuple.
auto getArgLocator = [&](unsigned argIdx, unsigned paramIdx)
-> ConstraintLocatorBuilder {
return locator.withPathElement(
LocatorPathElt::getApplyArgToParam(argIdx, paramIdx));
};
// Local function to set the ith argument of the argument.
auto setArgElement = [&](unsigned i, Expr *e) {
if (argTuple) {
argTuple->setElement(i, e);
return;
}
assert(i == 0 && "Scalar with more than one argument?");
if (argParen) {
argParen->setSubExpr(e);
return;
}
arg = e;
};
auto &tc = getConstraintSystem().getTypeChecker();
bool anythingShuffled = false;
SmallVector<TupleTypeElt, 4> toSugarFields;
SmallVector<TupleTypeElt, 4> fromTupleExprFields(
argTuple? argTuple->getNumElements() : 1);
SmallVector<ScalarToTupleExpr::Element, 4> scalarToTupleElements;
SmallVector<Expr *, 2> callerDefaultArgs;
ConcreteDeclRef defaultArgsOwner = nullptr;
Expr *injectionFn = nullptr;
SmallVector<int, 4> sources;
for (unsigned paramIdx = 0, numParams = parameterBindings.size();
paramIdx != numParams; ++paramIdx) {
// Extract the parameter.
const auto &param = paramTuple[paramIdx];
// Handle variadic parameters.
if (param.isVararg()) {
// FIXME: TupleShuffleExpr cannot handle variadics anywhere other than
// at the end.
if (paramIdx != numParams-1) {
tc.diagnose(arg->getLoc(), diag::tuple_conversion_not_expressible,
arg->getType(), paramType);
return nullptr;
}
// Find the appropriate injection function.
ArraySliceType *sliceType
= cast<ArraySliceType>(param.getType().getPointer());
Type boundType = BuiltinIntegerType::getWordType(tc.Context);
injectionFn = tc.buildArrayInjectionFnRef(cs.DC,
sliceType, boundType,
arg->getStartLoc());
if (!injectionFn)
return nullptr;
// Record this parameter.
toSugarFields.push_back(param);
anythingShuffled = true;
sources.push_back(TupleShuffleExpr::FirstVariadic);
// Convert the arguments.
auto paramBaseType = param.getVarargBaseTy();
for (auto argIdx : parameterBindings[paramIdx]) {
auto arg = getArg(argIdx);
auto argType = arg->getType();
sources.push_back(argIdx);
// If the argument type exactly matches, this just works.
if (argType->isEqual(paramBaseType)) {
fromTupleExprFields[argIdx] = TupleTypeElt(argType,
getArgLabel(argIdx));
scalarToTupleElements.push_back(ScalarToTupleExpr::Element());
continue;
}
// FIXME: If we're not converting directly from a tuple expression,
// we can't express this. LAME!
if (!argTuple && numParams > 1) {
tc.diagnose(arg->getLoc(),
diag::tuple_conversion_not_expressible,
arg->getType(), paramType);
return nullptr;
}
// Convert the argument.
auto convertedArg = coerceToType(arg, paramBaseType,
getArgLocator(argIdx, paramIdx));
if (!convertedArg)
return nullptr;
// Add the converted argument.
setArgElement(argIdx, convertedArg);
fromTupleExprFields[argIdx] = TupleTypeElt(convertedArg->getType(),
getArgLabel(argIdx));
scalarToTupleElements.push_back(ScalarToTupleExpr::Element());
}
continue;
}
// If we are using a default argument, handle it now.
if (parameterBindings[paramIdx].empty()) {
// Dig out the owner of the default arguments.
if (!defaultArgsOwner) {
defaultArgsOwner
= findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator));
assert(defaultArgsOwner && "Missing default arguments owner?");
} else {
assert(findDefaultArgsOwner(cs, solution,
cs.getConstraintLocator(locator))
== defaultArgsOwner);
}
// Note that we'll be doing a shuffle involving default arguments.
anythingShuffled = true;
toSugarFields.push_back(param);
// Create a caller-side default argument, if we need one.
if (auto defArg = getCallerDefaultArg(tc, dc, arg->getLoc(),
defaultArgsOwner, paramIdx)) {
callerDefaultArgs.push_back(defArg);
sources.push_back(TupleShuffleExpr::CallerDefaultInitialize);
scalarToTupleElements.push_back(defArg);
} else {
sources.push_back(TupleShuffleExpr::DefaultInitialize);
scalarToTupleElements.push_back(defaultArgsOwner);
}
continue;
}
// Extract the argument used to initialize this parameter.
assert(parameterBindings[paramIdx].size() == 1);
unsigned argIdx = parameterBindings[paramIdx].front();
auto arg = getArg(argIdx);
auto argType = arg->getType();
// If the argument and parameter indices differ, or if the names differ,
// this is a shuffle.
sources.push_back(argIdx);
if (argIdx != paramIdx || getArgLabel(argIdx) != param.getName()) {
anythingShuffled = true;
}
scalarToTupleElements.push_back(ScalarToTupleExpr::Element());
// If the types exactly match, this is easy.
auto paramType = param.getType();
if (argType->isEqual(paramType)) {
toSugarFields.push_back(TupleTypeElt(argType, param.getName()));
fromTupleExprFields[argIdx] = TupleTypeElt(paramType, param.getName());
continue;
}
// Convert the argument.
auto convertedArg = coerceToType(arg, paramType, getArgLocator(argIdx,
paramIdx));
if (!convertedArg)
return nullptr;
// Add the converted argument.
setArgElement(argIdx, convertedArg);
fromTupleExprFields[argIdx] = TupleTypeElt(convertedArg->getType(),
getArgLabel(argIdx));
toSugarFields.push_back(TupleTypeElt(argType, param.getName()));
}
// Compute the updated 'from' tuple type, since we may have
// performed some conversions in place.
Type argTupleType = TupleType::get(fromTupleExprFields, tc.Context);
if (argTuple) {
argTuple->setType(anythingShuffled? argTupleType : paramType);
} else {
arg->setType(anythingShuffled? argTupleType : paramType);
}
// If we don't have to shuffle anything, we're done.
if (!anythingShuffled)
return arg;
// If we came from a scalar, create a scalar-to-tuple conversion.
if (!argTuple) {
auto elements = tc.Context.AllocateCopy(scalarToTupleElements);
return new (tc.Context) ScalarToTupleExpr(arg, paramType, elements,
injectionFn);
}
// Create the tuple shuffle.
ArrayRef<int> mapping = tc.Context.AllocateCopy(sources);
auto callerDefaultArgsCopy = tc.Context.AllocateCopy(callerDefaultArgs);
auto shuffle = new (tc.Context) TupleShuffleExpr(arg, mapping,
defaultArgsOwner,
callerDefaultArgsCopy,
paramType);
shuffle->setVarargsInjectionFunction(injectionFn);
return shuffle;
}
Expr *ExprRewriter::coerceToType(Expr *expr, Type toType,
ConstraintLocatorBuilder locator) {
auto &tc = cs.getTypeChecker();
// The type we're converting from.
Type fromType = expr->getType();
// If the types are already equivalent, we don't have to do anything.
if (fromType->isEqual(toType))
return expr;
// If the solver recorded what we should do here, just do it immediately.
auto knownRestriction = solution.ConstraintRestrictions.find(
{ fromType->getCanonicalType(),
toType->getCanonicalType() });
if (knownRestriction != solution.ConstraintRestrictions.end()) {
switch (knownRestriction->second) {
case ConversionRestrictionKind::TupleToTuple: {
auto fromTuple = expr->getType()->castTo<TupleType>();
auto toTuple = toType->castTo<TupleType>();
SmallVector<int, 4> sources;
SmallVector<unsigned, 4> variadicArgs;
bool failed = computeTupleShuffle(fromTuple, toTuple, sources,
variadicArgs,
hasMandatoryTupleLabels(expr));
assert(!failed && "Couldn't convert tuple to tuple?");
(void)failed;
return coerceTupleToTuple(expr, fromTuple, toTuple, locator, sources,
variadicArgs);
}
case ConversionRestrictionKind::ScalarToTuple: {
auto toTuple = toType->castTo<TupleType>();
return coerceScalarToTuple(expr, toTuple,
toTuple->getFieldForScalarInit(), locator);
}
case ConversionRestrictionKind::TupleToScalar: {
// If this was a single-element tuple expression, reach into that
// subexpression.
// FIXME: This is a hack to deal with @lvalue-ness issues. It loses
// source information.
if (auto fromTupleExpr = dyn_cast<TupleExpr>(expr)) {
if (fromTupleExpr->getNumElements() == 1) {
return coerceToType(fromTupleExpr->getElement(0), toType,
locator.withPathElement(
LocatorPathElt::getTupleElement(0)));
}
}
// Extract the element.
auto fromTuple = fromType->castTo<TupleType>();
expr = new (cs.getASTContext()) TupleElementExpr(
expr,
expr->getLoc(),
0,
expr->getLoc(),
fromTuple->getElementType(0));
expr->setImplicit(true);
// Coerce the element to the expected type.
return coerceToType(expr, toType,
locator.withPathElement(
LocatorPathElt::getTupleElement(0)));
}
case ConversionRestrictionKind::DeepEquality:
llvm_unreachable("Equality handled above");
case ConversionRestrictionKind::Superclass: {
// Coercion from archetype to its (concrete) superclass.
if (auto fromArchetype = fromType->getAs<ArchetypeType>()) {
expr = new (tc.Context) ArchetypeToSuperExpr(
expr,
fromArchetype->getSuperclass());
// If we are done succeeded, use the coerced result.
if (expr->getType()->isEqual(toType)) {
return expr;
}
fromType = expr->getType();
}
// Coercion from subclass to superclass.
return new (tc.Context) DerivedToBaseExpr(expr, toType);
}
case ConversionRestrictionKind::LValueToRValue: {
// Load from the lvalue.
expr = new (tc.Context) LoadExpr(expr, fromType->getRValueType());
// Coerce the result.
return coerceToType(expr, toType, locator);
}
case ConversionRestrictionKind::Existential:
return coerceExistential(expr, toType, locator);
case ConversionRestrictionKind::ClassMetatypeToAnyObject: {
return new (tc.Context) ClassMetatypeToObjectExpr(expr, toType);
}
case ConversionRestrictionKind::ExistentialMetatypeToAnyObject: {
return new (tc.Context) ExistentialMetatypeToObjectExpr(expr, toType);
}
case ConversionRestrictionKind::ProtocolMetatypeToProtocolClass: {
return new (tc.Context) ProtocolMetatypeToObjectExpr(expr, toType);
}
case ConversionRestrictionKind::ValueToOptional: {
auto toGenericType = toType->castTo<BoundGenericType>();
assert(toGenericType->getDecl()->classifyAsOptionalType());
tc.requireOptionalIntrinsics(expr->getLoc());
Type valueType = toGenericType->getGenericArgs()[0];
expr = coerceToType(expr, valueType, locator);
if (!expr) return nullptr;
auto *result = new (tc.Context) InjectIntoOptionalExpr(expr, toType);
diagnoseOptionalInjection(result);
return result;
}
case ConversionRestrictionKind::OptionalToImplicitlyUnwrappedOptional:
case ConversionRestrictionKind::ImplicitlyUnwrappedOptionalToOptional:
case ConversionRestrictionKind::OptionalToOptional:
return coerceOptionalToOptional(expr, toType, locator);
case ConversionRestrictionKind::ForceUnchecked: {
auto valueTy = fromType->getImplicitlyUnwrappedOptionalObjectType();
assert(valueTy);
expr = coerceImplicitlyUnwrappedOptionalToValue(expr, valueTy, locator);
if (!expr) return nullptr;
return coerceToType(expr, toType, locator);
}
case ConversionRestrictionKind::ArrayUpcast: {
// Look through implicitly unwrapped optionals.
if (auto objTy
= cs.lookThroughImplicitlyUnwrappedOptionalType(
expr->getType())) {
expr = coerceImplicitlyUnwrappedOptionalToValue(expr, objTy, locator);
if (!expr) return nullptr;
}
// Form the upcast.
bool isBridged = !cs.getBaseTypeForArrayType(fromType.getPointer())
->isBridgeableObjectType();
return new (tc.Context) CollectionUpcastConversionExpr(expr, toType,
isBridged);
}
case ConversionRestrictionKind::DictionaryUpcast: {
// Look through implicitly unwrapped optionals.
if (auto objTy
= cs.lookThroughImplicitlyUnwrappedOptionalType(expr->getType())) {
expr = coerceImplicitlyUnwrappedOptionalToValue(expr, objTy, locator);
if (!expr) return nullptr;
}
// If the source key and value types are object types, this is an upcast.
// Otherwise, it's bridged.
Type sourceKey, sourceValue;
std::tie(sourceKey, sourceValue) = *cs.isDictionaryType(expr->getType());
bool isBridged = !sourceKey->isBridgeableObjectType() ||
!sourceValue->isBridgeableObjectType();
return new (tc.Context) CollectionUpcastConversionExpr(expr, toType,
isBridged);
}
case ConversionRestrictionKind::User: {
tc.requirePointerArgumentIntrinsics(expr->getLoc());
return coerceViaUserConversion(expr, toType, locator);
}
case ConversionRestrictionKind::InoutToPointer: {
tc.requirePointerArgumentIntrinsics(expr->getLoc());
return new (tc.Context) InOutToPointerExpr(expr, toType);
}
case ConversionRestrictionKind::ArrayToPointer: {
tc.requirePointerArgumentIntrinsics(expr->getLoc());
return new (tc.Context) ArrayToPointerExpr(expr, toType);
}
case ConversionRestrictionKind::StringToPointer: {
tc.requirePointerArgumentIntrinsics(expr->getLoc());
return new (tc.Context) StringToPointerExpr(expr, toType);
}
case ConversionRestrictionKind::PointerToPointer: {
tc.requirePointerArgumentIntrinsics(expr->getLoc());
return new (tc.Context) PointerToPointerExpr(expr, toType);
}
case ConversionRestrictionKind::BridgeToObjC: {
Expr *objcExpr = bridgeToObjectiveC(expr);
if (!objcExpr)
return nullptr;
return coerceToType(objcExpr, toType, locator);
}
case ConversionRestrictionKind::BridgeFromObjC:
return bridgeFromObjectiveC(expr, toType);
}
}
// Tuple-to-scalar conversion.
// FIXME: Will go away when tuple labels go away.
if (auto fromTuple = fromType->getAs<TupleType>()) {
if (fromTuple->getNumElements() == 1 &&
!fromTuple->getFields()[0].isVararg() &&
!toType->is<TupleType>()) {
expr = new (cs.getASTContext()) TupleElementExpr(
expr,
expr->getLoc(),
0,
expr->getLoc(),
fromTuple->getElementType(0));
expr->setImplicit(true);
}
}
// Coercions from an lvalue: load or perform implicit address-of. We perform
// these coercions first because they are often the first step in a multi-step
// coercion.
if (auto fromLValue = fromType->getAs<LValueType>()) {
if (auto *toIO = toType->getAs<InOutType>()) {
(void)toIO;
// In an 'inout' operator like "++i", the operand is converted from
// an implicit lvalue to an inout argument.
assert(toIO->getObjectType()->isEqual(fromLValue->getObjectType()));
return new (tc.Context) InOutExpr(expr->getStartLoc(), expr,
toType, /*isImplicit*/true);
}
// If we're actually turning this into an lvalue tuple element, don't
// load.
bool performLoad = true;
if (auto toTuple = toType->getAs<TupleType>()) {
int scalarIdx = toTuple->getFieldForScalarInit();
if (scalarIdx >= 0 &&
toTuple->getElementType(scalarIdx)->is<InOutType>())
performLoad = false;
}
if (performLoad) {
// Load from the lvalue.
expr = new (tc.Context) LoadExpr(expr, fromLValue->getObjectType());
// Coerce the result.
return coerceToType(expr, toType, locator);
}
}
// Coercions to tuple type.
if (auto toTuple = toType->getAs<TupleType>()) {
// Coerce from a tuple to a tuple.
if (auto fromTuple = fromType->getAs<TupleType>()) {
SmallVector<int, 4> sources;
SmallVector<unsigned, 4> variadicArgs;
if (!computeTupleShuffle(fromTuple, toTuple, sources, variadicArgs,
hasMandatoryTupleLabels(expr))) {
return coerceTupleToTuple(expr, fromTuple, toTuple,
locator, sources, variadicArgs);
}
}
// Coerce scalar to tuple.
int toScalarIdx = toTuple->getFieldForScalarInit();
if (toScalarIdx != -1) {
return coerceScalarToTuple(expr, toTuple, toScalarIdx, locator);
}
}
// Coercion from a subclass to a superclass.
if (fromType->mayHaveSuperclass() &&
toType->getClassOrBoundGenericClass()) {
for (auto fromSuperClass = tc.getSuperClassOf(fromType);
fromSuperClass;
fromSuperClass = tc.getSuperClassOf(fromSuperClass)) {
if (fromSuperClass->isEqual(toType)) {
// Coercion from archetype to its (concrete) superclass.
if (auto fromArchetype = fromType->getAs<ArchetypeType>()) {
expr = new (tc.Context) ArchetypeToSuperExpr(
expr,
fromArchetype->getSuperclass());
// If we succeeded, use the coerced result.
if (expr->getType()->isEqual(toType))
return expr;
}
// Coercion from subclass to superclass.
expr = new (tc.Context) DerivedToBaseExpr(expr, toType);
return expr;
}
}
}
// Coercions to function type.
if (auto toFunc = toType->getAs<FunctionType>()) {
// Coercion to an autoclosure type produces an implicit closure.
// FIXME: The type checker is more lenient, and allows @autoclosures to
// be subtypes of non-@autoclosures, which is bogus.
if (toFunc->isAutoClosure()) {
// Convert the value to the expected result type of the function.
expr = coerceToType(expr, toFunc->getResult(),
locator.withPathElement(ConstraintLocator::Load));
// We'll set discriminator values on all the autoclosures in a
// later pass.
auto discriminator = AutoClosureExpr::InvalidDiscriminator;
auto Closure = new (tc.Context) AutoClosureExpr(expr, toType,
discriminator, dc);
Pattern *pattern = TuplePattern::create(tc.Context, expr->getLoc(),
ArrayRef<TuplePatternElt>(),
expr->getLoc());
pattern->setType(TupleType::getEmpty(tc.Context));
Closure->setParams(pattern);
// Compute the capture list, now that we have analyzed the expression.
tc.computeCaptures(Closure);
return Closure;
}
// Coercion from one function type to another.
auto fromFunc = fromType->getAs<FunctionType>();
if (fromFunc) {
return new (tc.Context) FunctionConversionExpr(expr, toType);
}
}
// Coercions from a type to an existential type.
if (toType->isExistentialType()) {
return coerceExistential(expr, toType, locator);
}
// Coercions to an existential metatype.
if (toType->is<ExistentialMetatypeType>()) {
return coerceExistentialMetatype(expr, toType, locator);
}
// Coercion to Optional<T>.
if (auto toGenericType = toType->getAs<BoundGenericType>()) {
if (toGenericType->getDecl()->classifyAsOptionalType()) {
tc.requireOptionalIntrinsics(expr->getLoc());
Type valueType = toGenericType->getGenericArgs()[0];
expr = coerceToType(expr, valueType, locator);
if (!expr) return nullptr;
auto *result = new (tc.Context) InjectIntoOptionalExpr(expr, toType);
diagnoseOptionalInjection(result);
return result;
}
}
// Coerce via conversion function or constructor.
if (fromType->getNominalOrBoundGenericNominal()||
fromType->is<ArchetypeType>() ||
toType->getNominalOrBoundGenericNominal() ||
toType->is<ArchetypeType>()) {
return coerceViaUserConversion(expr, toType, locator);
}
// Coercion from one metatype to another.
if (fromType->is<MetatypeType>()) {
auto toMeta = toType->castTo<MetatypeType>();
return new (tc.Context) MetatypeConversionExpr(expr, toMeta);
}
llvm_unreachable("Unhandled coercion");
}
Expr *
ExprRewriter::coerceObjectArgumentToType(Expr *expr,
Type baseTy, ValueDecl *member,
bool IsDirectPropertyAccess,
ConstraintLocatorBuilder locator) {
Type toType = adjustSelfTypeForMember(baseTy, member, IsDirectPropertyAccess,
dc);
// If our expression already has the right type, we're done.
Type fromType = expr->getType();
if (fromType->isEqual(toType))
return expr;
// If we're coercing to an rvalue type, just do it.
if (!toType->is<InOutType>())
return coerceToType(expr, toType, locator);
assert(fromType->is<LValueType>() && "Can only convert lvalues to inout");
auto &ctx = cs.getTypeChecker().Context;
// Use InOutExpr to convert it to an explicit inout argument for the
// receiver.
return new (ctx) InOutExpr(expr->getStartLoc(), expr,
toType, /*isImplicit*/true);
}
Expr *ExprRewriter::convertLiteral(Expr *literal,
Type type,
Type openedType,
ProtocolDecl *protocol,
TypeOrName literalType,
Identifier literalFuncName,
ProtocolDecl *builtinProtocol,
TypeOrName builtinLiteralType,
Identifier builtinLiteralFuncName,
bool (*isBuiltinArgType)(Type),
Diag<> brokenProtocolDiag,
Diag<> brokenBuiltinProtocolDiag) {
auto &tc = cs.getTypeChecker();
// Check whether this literal type conforms to the builtin protocol.
ProtocolConformance *builtinConformance = nullptr;
if (builtinProtocol &&
tc.conformsToProtocol(type, builtinProtocol, cs.DC, &builtinConformance)){
// Find the builtin argument type we'll use.
Type argType;
if (builtinLiteralType.is<Type>())
argType = builtinLiteralType.get<Type>();
else
argType = tc.getWitnessType(type, builtinProtocol,
builtinConformance,
builtinLiteralType.get<Identifier>(),
brokenBuiltinProtocolDiag);
if (!argType)
return nullptr;
// Make sure it's of an appropriate builtin type.
if (isBuiltinArgType && !isBuiltinArgType(argType)) {
tc.diagnose(builtinProtocol->getLoc(), brokenBuiltinProtocolDiag);
return nullptr;
}
// The literal expression has this type.
literal->setType(argType);
// Call the builtin conversion operation.
// FIXME: Bogus location info.
Expr *base = TypeExpr::createImplicitHack(literal->getLoc(), type,
tc.Context);
Expr *result = tc.callWitness(base, dc,
builtinProtocol, builtinConformance,
builtinLiteralFuncName,
literal,
brokenBuiltinProtocolDiag);
if (result)
result->setType(type);
return result;
}
// This literal type must conform to the (non-builtin) protocol.
assert(protocol && "requirements should have stopped recursion");
ProtocolConformance *conformance = nullptr;
bool conforms = tc.conformsToProtocol(type, protocol, cs.DC, &conformance);
assert(conforms && "must conform to literal protocol");
(void)conforms;
// Figure out the (non-builtin) argument type if there is one.
Type argType;
if (literalType.is<Identifier>() &&
literalType.get<Identifier>().empty()) {
// If there is no argument to the constructor function, then just pass in
// the empty tuple.
literal = TupleExpr::createEmpty(tc.Context, literal->getLoc(),
literal->getLoc(), /*implicit*/true);
} else {
// Otherwise, figure out the type of the constructor function and coerce to
// it.
if (literalType.is<Type>())
argType = literalType.get<Type>();
else
argType = tc.getWitnessType(type, protocol, conformance,
literalType.get<Identifier>(),
brokenProtocolDiag);
if (!argType)
return nullptr;
// Convert the literal to the non-builtin argument type via the
// builtin protocol, first.
// FIXME: Do we need an opened type here?
literal = convertLiteral(literal, argType, argType, nullptr, Identifier(),
Identifier(), builtinProtocol,
builtinLiteralType, builtinLiteralFuncName,
isBuiltinArgType, brokenProtocolDiag,
brokenBuiltinProtocolDiag);
if (!literal)
return nullptr;
}
// Convert the resulting expression to the final literal type.
// FIXME: Bogus location info.
Expr *base = TypeExpr::createImplicitHack(literal->getLoc(), type,
tc.Context);
literal = tc.callWitness(base, dc,
protocol, conformance, literalFuncName,
literal, brokenProtocolDiag);
if (literal)
literal->setType(type);
return literal;
}
Expr *ExprRewriter::finishApply(ApplyExpr *apply, Type openedType,
ConstraintLocatorBuilder locator) {
TypeChecker &tc = cs.getTypeChecker();
auto fn = apply->getFn();
// The function is always an rvalue.
fn = tc.coerceToRValue(fn);
assert(fn && "Rvalue conversion failed?");
if (!fn)
return nullptr;
// Handle applications that implicitly look through ImplicitlyUnwrappedOptional<T>.
if (auto fnTy = cs.lookThroughImplicitlyUnwrappedOptionalType(fn->getType())) {
fn = coerceImplicitlyUnwrappedOptionalToValue(fn, fnTy, locator);
if (!fn) return nullptr;
}
// If we're applying a function that resulted from a covariant
// function conversion, strip off that conversion.
// FIXME: It would be nicer if we could build the ASTs properly in the
// first shot.
Type covariantResultType;
if (auto covariant = dyn_cast<CovariantFunctionConversionExpr>(fn)) {
// Strip off one layer of application from the covariant result.
covariantResultType
= covariant->getType()->castTo<AnyFunctionType>()->getResult();
// Use the subexpression as the function.
fn = covariant->getSubExpr();
}
apply->setFn(fn);
// Check whether the argument is 'super'.
bool isSuper = apply->getArg()->isSuperExpr();
// For function application, convert the argument to the input type of
// the function.
if (auto fnType = fn->getType()->getAs<FunctionType>()) {
auto origArg = apply->getArg();
Expr *arg = coerceCallArguments(origArg, fnType->getInput(),
locator.withPathElement(
ConstraintLocator::ApplyArgument));
if (!arg) {
return nullptr;
}
apply->setArg(arg);
apply->setType(fnType->getResult());
apply->setIsSuper(isSuper);
assert(!apply->getType()->is<PolymorphicFunctionType>() &&
"Polymorphic function type slipped through");
Expr *result = tc.substituteInputSugarTypeForResult(apply);
// If the result is an archetype from an opened existential, erase
// the existential and create the OpenExistentialExpr.
// FIXME: This is a localized form of a much more general rule for
// placement of open existential expressions. It only works for
// DynamicSelf.
OptionalTypeKind optKind;
auto resultTy = result->getType();
if (auto optValueTy = resultTy->getAnyOptionalObjectType(optKind)) {
resultTy = optValueTy;
}
if (auto archetypeTy = resultTy->getAs<ArchetypeType>()) {
auto opened = OpenedExistentials.find(archetypeTy);
if (opened != OpenedExistentials.end()) {
// Erase the archetype to its corresponding existential:
auto openedTy = archetypeTy->getOpenedExistentialType();
// - Drill down to the optional value (if necessary).
if (optKind) {
result = new (tc.Context) BindOptionalExpr(result,
result->getEndLoc(),
0, archetypeTy);
result->setImplicit(true);
}
// - Coerce to an existential value.
result = coerceToType(result, openedTy, locator);
if (!result)
return result;
// - Bind up the result back up as an optional (if necessary).
if (optKind) {
Type optOpenedTy = OptionalType::get(optKind, openedTy);
result = new (tc.Context) InjectIntoOptionalExpr(result, optOpenedTy);
result = new (tc.Context) OptionalEvaluationExpr(result, optOpenedTy);
}
// Create the expression that opens the existential.
result = new (tc.Context) OpenExistentialExpr(
opened->second.ExistentialValue,
opened->second.OpaqueValue,
result);
// Remove this from the set of opened existentials.
OpenedExistentials.erase(opened);
}
}
// If we have a covariant result type, perform the conversion now.
if (covariantResultType) {
if (covariantResultType->is<FunctionType>())
result = new (tc.Context) CovariantFunctionConversionExpr(
result,
covariantResultType);
else
result = new (tc.Context) CovariantReturnConversionExpr(
result,
covariantResultType);
}
return result;
}
// We have a type constructor.
auto metaTy = fn->getType()->castTo<AnyMetatypeType>();
auto ty = metaTy->getInstanceType();
// If we're "constructing" a tuple type, it's simply a conversion.
if (auto tupleTy = ty->getAs<TupleType>()) {
// FIXME: Need an AST to represent this properly.
return coerceToType(apply->getArg(), tupleTy, locator);
}
// We're constructing a value of nominal type. Look for the constructor or
// enum element to use.
assert(ty->getNominalOrBoundGenericNominal() || ty->is<DynamicSelfType>() ||
ty->is<ArchetypeType>() || ty->isExistentialType());
auto selected = getOverloadChoiceIfAvailable(
cs.getConstraintLocator(
locator.withPathElement(
ConstraintLocator::ConstructorMember)));
// We have the constructor.
auto choice = selected->choice;
auto decl = choice.getDecl();
// Consider the constructor decl reference expr 'implicit', but the
// constructor call expr itself has the apply's 'implicitness'.
Expr *declRef = buildMemberRef(fn,
selected->openedFullType,
/*DotLoc=*/SourceLoc(),
decl, fn->getEndLoc(),
selected->openedType, locator,
/*Implicit=*/true, /*direct ivar*/false);
declRef->setImplicit(apply->isImplicit());
apply->setFn(declRef);
// If we're constructing a class object, either the metatype must be
// statically derived (rather than an arbitrary value of metatype type) or
// the referenced constructor must be abstract.
if ((ty->getClassOrBoundGenericClass() || ty->is<DynamicSelfType>()) &&
!fn->isStaticallyDerivedMetatype() &&
!decl->hasClangNode() &&
!cast<ConstructorDecl>(decl)->isRequired()) {
tc.diagnose(apply->getLoc(), diag::dynamic_construct_class, ty)
.highlight(fn->getSourceRange());
auto ctor = cast<ConstructorDecl>(decl);
// FIXME: Better description of the initializer than just it's type.
if (ctor->isImplicit())
tc.diagnose(decl, diag::note_nonrequired_implicit_initializer,
ctor->getArgumentType());
else
tc.diagnose(decl, diag::note_nonrequired_initializer);
} else if (isa<ConstructorDecl>(decl) && ty->isExistentialType() &&
fn->isStaticallyDerivedMetatype()) {
tc.diagnose(apply->getLoc(), diag::static_construct_existential, ty)
.highlight(fn->getSourceRange());
}
// Tail-recur to actually call the constructor.
return finishApply(apply, openedType, locator);
}
/// Diagnose a relabel-tuple
///
/// \returns true if we successfully diagnosed the issue.
static bool diagnoseRelabel(TypeChecker &tc, Expr *expr,
ArrayRef<Identifier> newNames,
bool isSubscript) {
auto tuple = dyn_cast<TupleExpr>(expr);
if (!tuple) {
if (newNames[0].empty()) {
// This is probably a conversion from a value of labeled tuple type to
// a scalar.
// FIXME: We want this issue to disappear completely when single-element
// labelled tuples go away.
if (auto tupleTy = expr->getType()->getRValueType()->getAs<TupleType>()) {
int scalarFieldIdx = tupleTy->getFieldForScalarInit();
if (scalarFieldIdx >= 0) {
auto &field = tupleTy->getFields()[scalarFieldIdx];
if (field.hasName()) {
llvm::SmallString<16> str;
str = ".";
str += field.getName().str();
auto insertLoc = Lexer::getLocForEndOfToken(tc.Context.SourceMgr,
expr->getEndLoc());
tc.diagnose(expr->getStartLoc(),
diag::extra_named_single_element_tuple,
field.getName().str())
.fixItInsert(insertLoc, str);
return true;
}
}
}
// We don't know what to do with this.
return false;
}
// This is a scalar-to-tuple conversion. Add the name. We "know"
// that we're inside a ParenExpr, because ParenExprs are required
// by the syntax and locator resolution looks through on level of
// them.
// Look through the paren expression, if there is one.
if (auto parenExpr = dyn_cast<ParenExpr>(expr))
expr = parenExpr->getSubExpr();
llvm::SmallString<16> str;
str += newNames[0].str();
str += ": ";
tc.diagnose(expr->getStartLoc(), diag::missing_argument_labels, false,
str.substr(0, str.size()-1), isSubscript)
.fixItInsert(expr->getStartLoc(), str);
return true;
}
// Figure out how many extraneous, missing, and wrong labels are in
// the call.
unsigned numExtra = 0, numMissing = 0, numWrong = 0;
unsigned n = std::max(tuple->getNumElements(), (unsigned)newNames.size());
llvm::SmallString<16> missingBuffer;
llvm::SmallString<16> extraBuffer;
for (unsigned i = 0; i != n; ++i) {
Identifier oldName;
if (i < tuple->getNumElements())
oldName = tuple->getElementName(i);
Identifier newName;
if (i < newNames.size())
newName = newNames[i];
if (oldName == newName)
continue;
if (oldName.empty()) {
++numMissing;
missingBuffer += newName.str();
missingBuffer += ":";
} else if (newName.empty()) {
++numExtra;
extraBuffer += oldName.str();
extraBuffer += ':';
} else
++numWrong;
}
// Emit the diagnostic.
assert(numMissing > 0 || numExtra > 0 || numWrong > 0);
llvm::SmallString<16> haveBuffer; // note: diagOpt has references to this
llvm::SmallString<16> expectedBuffer; // note: diagOpt has references to this
Optional<InFlightDiagnostic> diagOpt;
// If we had any wrong labels, or we have both missing and extra labels,
// emit the catch-all "wrong labels" diagnostic.
bool plural = (numMissing + numExtra + numWrong) > 1;
if (numWrong > 0 || (numMissing > 0 && numExtra > 0)) {
for(unsigned i = 0, n = tuple->getNumElements(); i != n; ++i) {
auto haveName = tuple->getElementName(i);
if (haveName.empty())
haveBuffer += '_';
else
haveBuffer += haveName.str();
haveBuffer += ':';
}
for (auto expected : newNames) {
if (expected.empty())
expectedBuffer += '_';
else
expectedBuffer += expected.str();
expectedBuffer += ':';
}
StringRef haveStr = haveBuffer;
StringRef expectedStr = expectedBuffer;
diagOpt.emplace(tc.diagnose(expr->getLoc(), diag::wrong_argument_labels,
plural, haveStr, expectedStr, isSubscript));
} else if (numMissing > 0) {
StringRef missingStr = missingBuffer;
diagOpt.emplace(tc.diagnose(expr->getLoc(), diag::missing_argument_labels,
plural, missingStr, isSubscript));
} else {
assert(numExtra > 0);
StringRef extraStr = extraBuffer;
diagOpt.emplace(tc.diagnose(expr->getLoc(), diag::extra_argument_labels,
plural, extraStr, isSubscript));
}
// Emit Fix-Its to correct the names.
auto &diag = *diagOpt;
for (unsigned i = 0, n = tuple->getNumElements(); i != n; ++i) {
Identifier oldName = tuple->getElementName(i);
Identifier newName;
if (i < newNames.size())
newName = newNames[i];
if (oldName == newName)
continue;
if (newName.empty()) {
// Delete the old name.
diag.fixItRemoveChars(tuple->getElementNameLocs()[i],
tuple->getElements()[i]->getStartLoc());
continue;
}
if (oldName.empty()) {
// Insert the name.
llvm::SmallString<16> str;
str += newName.str();
str += ": ";
diag.fixItInsert(tuple->getElements()[i]->getStartLoc(), str);
continue;
}
// Change the name.
diag.fixItReplace(tuple->getElementNameLocs()[i], newName.str());
}
// FIXME: Fix AST.
return true;
}
/// \brief Apply a given solution to the expression, producing a fully
/// type-checked expression.
Expr *ConstraintSystem::applySolution(Solution &solution, Expr *expr) {
// If any fixes needed to be applied to arrive at this solution, resolve
// them to specific expressions.
if (!solution.Fixes.empty()) {
bool diagnosed = false;
for (auto fix : solution.Fixes) {
// Some fixes need more information from the locator itself, including
// tweaking the locator. Deal with those now.
ConstraintLocator *locator = fix.second;
// Removing a nullary call to a non-function requires us to have an
// 'ApplyFunction', which we strip.
if (fix.first.getKind() == FixKind::RemoveNullaryCall) {
auto anchor = locator->getAnchor();
auto path = locator->getPath();
if (!path.empty() &&
path.back().getKind() == ConstraintLocator::ApplyFunction) {
locator = getConstraintLocator(anchor, path.slice(0, path.size()-1),
locator->getSummaryFlags());
} else {
continue;
}
}
// Resolve the locator to a specific expression.
SourceRange range1, range2;
ConstraintLocator *resolved
= simplifyLocator(*this, locator, range1, range2);
// If we didn't manage to resolve directly to an expression, we don't
// have a great diagnostic to give, so continue.
if (!resolved || !resolved->getAnchor() || !resolved->getPath().empty())
continue;
Expr *affected = resolved->getAnchor();
switch (fix.first.getKind()) {
case FixKind::None:
llvm_unreachable("no-fix marker should never make it into solution");
case FixKind::NullaryCall: {
// Dig for the function we want to call.
auto type = solution.simplifyType(TC, affected->getType())
->getRValueType();
if (auto tupleTy = type->getAs<TupleType>()) {
if (auto tuple = dyn_cast<TupleExpr>(affected))
affected = tuple->getElement(0);
type = tupleTy->getFields()[0].getType()->getRValueType();
}
if (auto optTy = type->getAnyOptionalObjectType())
type = optTy;
if (type->is<AnyFunctionType>()) {
type = type->castTo<AnyFunctionType>()->getResult();
}
SourceLoc afterAffectedLoc
= Lexer::getLocForEndOfToken(TC.Context.SourceMgr,
affected->getEndLoc());
TC.diagnose(affected->getLoc(), diag::missing_nullary_call, type)
.fixItInsert(afterAffectedLoc, "()");
diagnosed = true;
break;
}
case FixKind::RemoveNullaryCall: {
if (auto apply = dyn_cast<ApplyExpr>(affected)) {
auto type = solution.simplifyType(TC, apply->getFn()->getType())
->getRValueObjectType();
TC.diagnose(affected->getLoc(), diag::extra_call_nonfunction, type)
.fixItRemove(apply->getArg()->getSourceRange());
diagnosed = true;
}
break;
}
case FixKind::ForceOptional: {
auto type = solution.simplifyType(TC, affected->getType())
->getRValueObjectType();
SourceLoc afterAffectedLoc
= Lexer::getLocForEndOfToken(TC.Context.SourceMgr,
affected->getEndLoc());
TC.diagnose(affected->getLoc(), diag::missing_unwrap_optional, type)
.fixItInsert(afterAffectedLoc, "!");
diagnosed = true;
break;
}
case FixKind::ForceDowncast: {
auto fromType = solution.simplifyType(TC, affected->getType())
->getRValueObjectType();
Type toType = solution.simplifyType(TC,
fix.first.getTypeArgument(*this));
SourceLoc afterAffectedLoc
= Lexer::getLocForEndOfToken(TC.Context.SourceMgr,
affected->getEndLoc());
llvm::SmallString<32> asCastStr;
asCastStr += " as ";
asCastStr += toType.getString();
TC.diagnose(affected->getLoc(), diag::missing_forced_downcast, fromType,
toType)
.fixItInsert(afterAffectedLoc, asCastStr);
diagnosed = true;
// FIXME: Add parentheses if we now need them.
break;
}
case FixKind::AddressOf: {
auto type = solution.simplifyType(TC, affected->getType())
->getRValueObjectType();
TC.diagnose(affected->getLoc(), diag::missing_address_of, type)
.fixItInsert(affected->getStartLoc(), "&");
diagnosed = true;
break;
}
case FixKind::TupleToScalar:
case FixKind::ScalarToTuple:
case FixKind::RelabelCallTuple: {
if (diagnoseRelabel(TC,affected,fix.first.getRelabelTupleNames(*this),
/*isSubscript=*/locator->getPath().back().getKind()
== ConstraintLocator::SubscriptIndex))
diagnosed = true;
break;
}
}
// FIXME: It would be really nice to emit a follow-up note showing where
// we got the other type information from, e.g., the parameter we're
// initializing.
}
if (diagnosed)
return nullptr;
// We didn't manage to diagnose anything well, so fall back to
// diagnosing mining the system to construct a reasonable error message.
this->diagnoseFailureFromConstraints(expr);
return nullptr;
}
class ExprWalker : public ASTWalker {
ExprRewriter &Rewriter;
unsigned LeftSideOfAssignment = 0;
public:
ExprWalker(ExprRewriter &Rewriter) : Rewriter(Rewriter) { }
std::pair<bool, Expr *> walkToExprPre(Expr *expr) override {
// For a default-value expression, do nothing.
if (isa<DefaultValueExpr>(expr))
return { false, expr };
// For closures, update the parameter types and check the body.
if (auto closure = dyn_cast<ClosureExpr>(expr)) {
Rewriter.simplifyExprType(expr);
auto &cs = Rewriter.getConstraintSystem();
auto &tc = cs.getTypeChecker();
// Coerce the pattern, in case we resolved something.
auto fnType = closure->getType()->castTo<FunctionType>();
Pattern *params = closure->getParams();
TypeResolutionOptions TROptions;
TROptions |= TR_OverrideType;
TROptions |= TR_FromNonInferredPattern;
if (tc.coercePatternToType(params, closure, fnType->getInput(),
TROptions))
return { false, nullptr };
closure->setParams(params);
// If this is a single-expression closure, convert the expression
// in the body to the result type of the closure.
if (closure->hasSingleExpressionBody()) {
// Enter the context of the closure when type-checking the body.
llvm::SaveAndRestore<DeclContext *> savedDC(Rewriter.dc, closure);
Expr *body = closure->getSingleExpressionBody()->walk(*this);
if (body)
body = Rewriter.coerceToType(body,
fnType->getResult(),
cs.getConstraintLocator(
closure,
ConstraintLocator::ClosureResult));
if (!body)
return { false, nullptr } ;
closure->setSingleExpressionBody(body);
} else {
// For other closures, type-check the body.
tc.typeCheckClosureBody(closure);
}
// Compute the capture list, now that we have type-checked the body.
tc.computeCaptures(closure);
return { false, closure };
}
// Track whether we're in the left-hand side of an assignment...
if (auto assign = dyn_cast<AssignExpr>(expr)) {
++LeftSideOfAssignment;
if (auto dest = assign->getDest()->walk(*this))
assign->setDest(dest);
else
return { false, nullptr };
--LeftSideOfAssignment;
auto &cs = Rewriter.getConstraintSystem();
auto srcLocator = cs.getConstraintLocator(
assign,
ConstraintLocator::AssignSource);
if (auto src = assign->getSrc()->walk(*this))
assign->setSrc(src);
else
return { false, nullptr };
expr = Rewriter.visitAssignExpr(assign, srcLocator);
return { false, expr };
}
// ...so we can verify that '_' only appears there.
if (isa<DiscardAssignmentExpr>(expr) && LeftSideOfAssignment == 0)
Rewriter.getConstraintSystem().getTypeChecker()
.diagnose(expr->getLoc(), diag::discard_expr_outside_of_assignment);
return { true, expr };
}
Expr *walkToExprPost(Expr *expr) override {
return Rewriter.visit(expr);
}
/// \brief Ignore statements.
std::pair<bool, Stmt *> walkToStmtPre(Stmt *stmt) override {
return { false, stmt };
}
/// \brief Ignore declarations.
bool walkToDeclPre(Decl *decl) override { return false; }
};
ExprRewriter rewriter(*this, solution);
ExprWalker walker(rewriter);
auto result = expr->walk(walker);
return result;
}
Expr *ConstraintSystem::applySolutionShallow(const Solution &solution,
Expr *expr) {
ExprRewriter rewriter(*this, solution);
return rewriter.visit(expr);
}
Expr *Solution::coerceToType(Expr *expr, Type toType,
ConstraintLocator *locator,
bool ignoreTopLevelInjection) const {
auto &cs = getConstraintSystem();
ExprRewriter rewriter(cs, *this);
Expr *result = rewriter.coerceToType(expr, toType, locator);
if (!result)
return nullptr;
// If we were asked to ignore top-level optional injections, mark
// the top-level injection (if any) as "diagnosed".
if (ignoreTopLevelInjection) {
if (auto injection = dyn_cast<InjectIntoOptionalExpr>(
result->getSemanticsProvidingExpr())) {
rewriter.DiagnosedOptionalInjections.insert(injection);
}
}
return result;
}
Expr *TypeChecker::callWitness(Expr *base, DeclContext *dc,
ProtocolDecl *protocol,
ProtocolConformance *conformance,
Identifier name,
MutableArrayRef<Expr *> arguments,
Diag<> brokenProtocolDiag) {
// Construct an empty constraint system and solution.
ConstraintSystem cs(*this, dc, ConstraintSystemOptions());
// Find the witness we need to use.
auto type = base->getType();
if (auto metaType = type->getAs<AnyMetatypeType>())
type = metaType->getInstanceType();
auto witness = findNamedWitness(*this, dc, type->getRValueType(), protocol,
name, brokenProtocolDiag);
if (!witness)
return nullptr;
// Form a reference to the witness itself.
Type openedFullType, openedType;
std::tie(openedFullType, openedType)
= cs.getTypeOfMemberReference(base->getType(), witness,
/*isTypeReference=*/false,
/*isDynamicResult=*/false);
auto locator = cs.getConstraintLocator(base);
// Form the call argument.
Expr *arg;
if (arguments.size() == 1)
arg = arguments[0];
else {
SmallVector<TupleTypeElt, 4> elementTypes;
for (auto elt : arguments)
elementTypes.push_back(TupleTypeElt(elt->getType()));
arg = TupleExpr::create(Context,
base->getStartLoc(),
arguments,
witness->getFullName().getArgumentNames(),
{ },
base->getEndLoc(),
/*hasTrailingClosure=*/false,
/*Implicit=*/true,
TupleType::get(elementTypes, Context));
}
// Add the conversion from the argument to the function parameter type.
cs.addConstraint(ConstraintKind::ArgumentTupleConversion, arg->getType(),
openedType->castTo<FunctionType>()->getInput(),
cs.getConstraintLocator(arg,
ConstraintLocator::ApplyArgument));
// Solve the system.
SmallVector<Solution, 1> solutions;
bool failed = cs.solve(solutions);
(void)failed;
assert(!failed && "Unable to solve for call to witness?");
Solution &solution = solutions.front();
ExprRewriter rewriter(cs, solution);
auto memberRef = rewriter.buildMemberRef(base, openedFullType,
base->getStartLoc(),
witness, base->getEndLoc(),
openedType, locator,
/*Implicit=*/true,
/*direct ivar*/false);
// Call the witness.
ApplyExpr *apply = new (Context) CallExpr(memberRef, arg, /*Implicit=*/true);
return rewriter.finishApply(apply, openedType,
cs.getConstraintLocator(arg));
}
/// \brief Convert an expression via a builtin protocol.
///
/// \param solution The solution to the expression's constraint system,
/// which must have included a constraint that the expression's type
/// conforms to the give \c protocol.
/// \param expr The expression to convert.
/// \param locator The locator describing where the conversion occurs.
/// \param protocol The protocol to use for conversion.
/// \param generalName The name of the protocol method to use for the
/// conversion.
/// \param builtinName The name of the builtin method to use for the
/// last step of the conversion.
/// \param brokenProtocolDiag Diagnostic to emit if the protocol
/// definition is missing.
/// \param brokenBuiltinDiag Diagnostic to emit if the builtin definition
/// is broken.
///
/// \returns the converted expression.
static Expr *convertViaBuiltinProtocol(const Solution &solution,
Expr *expr,
ConstraintLocator *locator,
ProtocolDecl *protocol,
Identifier generalName,
Identifier builtinName,
Diag<> brokenProtocolDiag,
Diag<> brokenBuiltinDiag) {
auto &cs = solution.getConstraintSystem();
ExprRewriter rewriter(cs, solution);
// FIXME: Cache name.
auto &tc = cs.getTypeChecker();
auto &ctx = tc.Context;
auto type = expr->getType();
// Look for the builtin name. If we don't have it, we need to call the
// general name via the witness table.
auto witnesses = tc.lookupMember(type->getRValueType(), builtinName, cs.DC);
if (!witnesses) {
// Find the witness we need to use.
auto witness =
findNamedPropertyWitness(tc, cs.DC, type -> getRValueType(), protocol,
generalName, brokenProtocolDiag);
// Form a reference to this member.
Expr *memberRef = new (ctx) MemberRefExpr(expr, expr->getStartLoc(),
witness, expr->getEndLoc(),
/*Implicit=*/true);
bool failed = tc.typeCheckExpressionShallow(memberRef, cs.DC);
if (failed) {
// If the member reference expression failed to type check, the Expr's
// type does not conform to the given protocol.
tc.diagnose(expr->getLoc(),
diag::type_does_not_conform,
type,
protocol->getType());
return nullptr;
}
expr = memberRef;
// At this point, we must have a type with the builtin member.
type = expr->getType();
witnesses = tc.lookupMember(type->getRValueType(), builtinName, cs.DC);
if (!witnesses) {
tc.diagnose(protocol->getLoc(), brokenProtocolDiag);
return nullptr;
}
}
// Find the builtin method.
if (witnesses.size() != 1) {
tc.diagnose(protocol->getLoc(), brokenBuiltinDiag);
return nullptr;
}
FuncDecl *builtinMethod = dyn_cast<FuncDecl>(witnesses[0]);
if (!builtinMethod) {
tc.diagnose(protocol->getLoc(), brokenBuiltinDiag);
return nullptr;
}
// Form a reference to the builtin method.
Expr *memberRef = new (ctx) MemberRefExpr(expr, SourceLoc(),
builtinMethod, expr->getLoc(),
/*Implicit=*/true);
bool failed = tc.typeCheckExpressionShallow(memberRef, cs.DC);
assert(!failed && "Could not reference witness?");
(void)failed;
// Call the builtin method.
Expr *arg = TupleExpr::createEmpty(ctx, expr->getStartLoc(),
expr->getEndLoc(), /*Implicit=*/true);
expr = new (ctx) CallExpr(memberRef, arg, /*Implicit=*/true);
failed = tc.typeCheckExpressionShallow(expr, cs.DC);
assert(!failed && "Could not call witness?");
(void)failed;
return expr;
}
Expr *
Solution::convertToLogicValue(Expr *expr, ConstraintLocator *locator) const {
auto &tc = getConstraintSystem().getTypeChecker();
// Special case: already a builtin logic value.
if (expr->getType()->getRValueType()->isBuiltinIntegerType(1)) {
return tc.coerceToRValue(expr);
}
// FIXME: Cache names.
auto result = convertViaBuiltinProtocol(
*this, expr, locator,
tc.getProtocol(expr->getLoc(),
KnownProtocolKind::BooleanType),
tc.Context.Id_BoolValue,
tc.Context.Id_GetBuiltinLogicValue,
diag::condition_broken_proto,
diag::broken_bool);
if (result && !result->getType()->isBuiltinIntegerType(1)) {
tc.diagnose(expr->getLoc(), diag::broken_bool);
return nullptr;
}
return result;
}
Expr *
Solution::convertOptionalToBool(Expr *expr, ConstraintLocator *locator) const {
auto &cs = getConstraintSystem();
ExprRewriter rewriter(cs, *this);
auto &tc = cs.getTypeChecker();
auto proto = tc.getProtocol(
expr->getLoc(), KnownProtocolKind::BooleanType);
// Find the witness we need to use.
Type type = expr->getType();
auto witness = findNamedPropertyWitness(tc, cs.DC, type -> getRValueType(),
proto, tc.Context.Id_BoolValue,
diag::condition_broken_proto);
// Form a reference to this member.
auto &ctx = tc.Context;
Expr *memberRef = new (ctx) MemberRefExpr(expr, expr->getStartLoc(),
witness, expr->getEndLoc(),
/*Implicit=*/true);
bool failed = tc.typeCheckExpressionShallow(memberRef, cs.DC);
if (failed) {
// If the member reference expression failed to type check, the Expr's
// type does not conform to the given protocol.
tc.diagnose(expr->getLoc(),
diag::type_does_not_conform,
type,
proto->getType());
return nullptr;
}
return memberRef;
}
Expr *
Solution::convertToArrayBound(Expr *expr, ConstraintLocator *locator) const {
auto &tc = getConstraintSystem().getTypeChecker();
auto result = convertViaBuiltinProtocol(
*this, expr, locator,
tc.getProtocol(expr->getLoc(),
KnownProtocolKind::ArrayBoundType),
tc.Context.Id_ArrayBoundValue,
tc.Context.Id_GetBuiltinArrayBoundValue,
diag::broken_array_bound_proto,
diag::broken_builtin_array_bound);
if (result && !result->getType()->is<BuiltinIntegerType>()) {
tc.diagnose(expr->getLoc(), diag::broken_builtin_array_bound);
return nullptr;
}
return result;
}
Reference in New Issue View Git Blame Copy Permalink